Paper Mario Reference
This is an easy reference for what each MSBT file means, and what it contains.
Fast section links: Sticker Star, Color Splash, The Origami King
Sticker Star
Sticker Star has 46 English dialogue files. It's a little excessive, considering how little dialogue this game has — some files don't even have any text. Note that, unlike the rest of the series, Sticker Star recieved a massive retranslation in the British version, where almost every line is different in some way.
- Enemy.msbt: Enemy names
 - global.msbt: Names of Stickers, Things, and Scraps, generic battle messages, shop dialogue, main menu, opening
 - global_event.msbt: Kersti's overworld hints
 - intermissions.msbt: Royal Sticker poems
 - porttown_harbor.msbt: Surfshine Harbor
 - SealHelp.msbt: Sticker descriptions
 - SealMuseum.msbt: Sticker Museum descriptions, song names, dialogue
 - StaffCredit.msbt: Staff credits titles and names
 - stg1_1.msbt: Warm Fuzzy Plains
 - stg1_2.msbt: Bouquet Gardens
 - stg1_3.msbt: Water's Edge Way
 - stg1_4.msbt: Hither Thither Hill
 - stg1_5.msbt: Whammino Mountain (this one has exactly one entry)
 - stg1_6.msbt: Goomba Fortress
 - stg2_1.msbt: Drybake Desert
 - stg2_2.msbt: Yoshi Sphynx
 - stg2_3.msbt: Sandshifter Ruins (no entires)
 - stg2_4.msbt: Damp Oasis
 - stg2_5.msbt: Drybake Stadium
 - stg3_1.msbt: Leaflitter Path
 - stg3_6.msbt: Wiggler's Tree House
 - stg3_10.msbt: Stump Glade, Snifit or Whiffit
 - stg3_11.msbt: Outlook Point
 - stg3_12.msbt: Whitecap Beach
 - stg3_2345789.msbt: The Bafflewood, Rustle Burrow, Tree Branch Trail
 - stg4_1.msbt: Snow Rise
 - stg4_2.msbt: Ice Flow (no entires)
 - stg4_3.msbt: The Enigmansion
 - stg4_4.msbt: Whiteout Valley
 - stg4_5.msbt: Bowser's Snow Fort
 - stg5_1.msbt: Shy Guy Jungle
 - stg5_2.msbt: Jungle Rapids
 - stg5_3.msbt: Long Fall Falls (no entires)
 - stg5_4.msbt: Chomp Ruins
 - stg5_5.msbt: Rugged Road
 - stg5_6.msbt: Rumble Volcano
 - stg6_1.msbt: Gate Cliff
 - stg6_2.msbt: Bowser Jr.'s Flotilla
 - stg6_3.msbt: Bowser's Sky Castle
 - town_epilogue.msbt: Decalburg epilogue (no entires)
 - town_feast.msbt: Decalburg (Sticker Fest grounds)
 - town_houses.msbt: Decalburg (house area)
 - town_other.msbt: Decalburg (Sling-a-Thing area)
 - town_prologue.msbt: Decalburg (prolougue)
 - town_square.msbt: Decalburg (main area)
 - worldmap.msbt: Location names, world map dialogue
 
Color Splash
Color Splash has 46 English dialogue files.
- B1.msbt.lz: Indigo Underground
 - B2.msbt.lz: Bloo Bay Beach
 - B3.msbt.lz: Dark Bloo Inn
 - B4.msbt.lz: Cobalt Base, Snifit or Whiffit
 - BattleEnemy.msbt.lz: Enemy idle dialogue in battle
 - BB.msbt.lz: Fort Cobalt
 - CardHelp.msbt.lz: Descriptions for Battle Cards, Things, and special items
 - DR.msbt.lz: Text related to the three Spinning-Door minigames
 - Enemy.msbt.lz: Enemy names
 - G1.msbt.lz: Mondo Woods
 - G2.msbt.lz: Sacred Forest
 - G3.msbt.lz: Green Energy Plant
 - G4.msbt.lz: Mossrock Theater
 - GB.msbt.lz: The Emerald Circus
 - Global.msbt.lz: Button prompts, world map notifications, shop dialogue, generic battle messages, Prisma Cafe dialogue
 - GlobalEvent.msbt.lz: Letters, Huey's overworld hints
 - ItemName.msbt.lz: Names for Battle Cards, Things, special items, and letters
 - JK.msbt.lz: Roshambo Temples
 - KP.msbt.lz: Black Bowser's Castle
 - O1.msbt.lz: Marmalade Valley
 - O2.msbt.lz: Kiwano Temple
 - O3.msbt.lz: Toad Trainworks
 - O4.msbt.lz: Tangerino Grill
 - OB.msbt.lz: Sunset Express
 - R1.msbt.lz: Ruddy Road
 - R2.msbt.lz: Cherry Lake
 - R3.msbt.lz: Redpepper Volcano
 - R4.msbt.lz: Redpepper Crater
 - RB.msbt.lz: The Crimson Tower
 - RescueKinopio.msbt.lz: Rescue Squad dialogue
 - StaffCredit.msbt.lz: Staff credits titles and names
 - SubStory.msbt.lz: Dialogue related to the Piper sidequest
 - Town1.msbt.lz: Port Prisma
 - TownGallery.msbt.lz: Prisma Museum
 - TownGalleryDisplay.msbt.lz: Prisma Museum art and music names
 - TownInfo.msbt.lz: Prisma Times, Deep Cuts, Know-it-All Toad hints
 - TownMR.msbt.lz: Big Paint Star memories
 - V1.msbt.lz: Plum Park
 - V2.msbt.lz: Violet Passage
 - V3.msbt.lz: Vortex Island
 - V4.msbt.lz: Lighthouse Island
 - VB.msbt.lz: Fortune Island
 - WorldMap.msbt.lz: Location names, world map UI
 - Y1.msbt.lz: Daffodil Peak
 - Y2.msbt.lz: Sunglow Ridge
 - Y3.msbt.lz: Chateau Chanterelle
 - Y4.msbt.lz: Mustard Cafe
 - YB.msbt.lz: The Golden Coliseum
 
The Origami King
The Origami King has 59 English dialogue files (not including msg.msbp). Note that the absence of W3C2 is not a mistake; there is no area that goes by this code in-game.
- announce.msbt: Announcements that appear on the pause menu
 - battle.msbt: Battle UI, warnings, hints
 - battle_Attack.msbt: Enemy attacks in battle
 - battle_Audience.msbt: Toad audience lines in battle
 - battle_Tutorial.msbt: Tutorial battles in Peach's Castle, Whispering Woods, and Picnic Road
 - battle_W1C3.msbt: Earth Vellumental boss battle
 - battle_W1C4.msbt: Colored Pencils boss battle
 - battle_W2C2.msbt: Water Vellumental boss battle
 - battle_W2C5.msbt: Rubber Band boss battle
 - battle_W3C3.msbt: Fire Vellumental boss battle
 - battle_W3C4.msbt: Hole Punch boss battle
 - battle_W4C2.msbt: Ice Vellumental boss battle
 - battle_W4C3.msbt: Tape boss battle
 - battle_W5C3.msbt: Handaconda and Scissors boss battles
 - battle_W5G1.msbt: Boss Sumo Bro boss battle
 - battle_W6C2.msbt: Stapler and King Olly boss battles
 - bench.msbt: Dialogue from the characters when sitting on benches
 - global.msbt: Common text, including warnings, button prompts, shop dialogue, fishing, and boss names
 - glossary.msbt: Terminology including names of locations, characters, bosses, items
 - hint.msbt: Olivia's overworld hints
 - item.msbt: Item descriptions and Collectible Treasure names
 - musuem.msbt: Musee Champignon descriptions and folded Toad names
 - museum_art.msbt: Musee Champignon art gallery names
 - museum_sound.msbt: Musee Champignon sound gallery names
 - staffcredit.msbt: Staff credits titles and names
 - ui.msbt: Pause menu, control popups, maps, options, Battle Lab menu
 - W0C1.msbt: Game intro, Peach's Castle, start of the ending
 - W1C1.msbt: Whispering Woods
 - W1C2.msbt: Graffiti Underground
 - W1C3.msbt: Earth Vellumental Temple
 - W1C4.msbt: Overlook Tower
 - W1G1.msbt: Toad Town
 - W1G2.msbt: Picnic Road
 - W1G3.msbt: Overlook Mountain, Bobby tram scene
 - W2C1.msbt: Chestnut Valley
 - W2C2.msbt: Water Vellumental Shrine
 - W2C3.msbt: Eddy River
 - W2C4.msbt: Ninja Attraction / House of Tricky Ninjas
 - W2C5.msbt: Big Sho' Theater
 - W2G1.msbt: Autumn Mountain
 - W2G2.msbt: Shogun Studios
 - W3C1.msbt: Breezy Tunnel
 - W3C3.msbt: Fire Vellumental Cave
 - W3C4.msbt: Temple of Shrooms
 - W3G1.msbt: Sweetpaper Valley
 - W3G2.msbt: Scorching Sandpaper Desert (plus Minor, East, West, Far East, Far West, and Shroom City / Snif City)
 - W4C1.msbt: The Princess Peach
 - W4C2.msbt: Ice Vellumental Mountain
 - W4C3.msbt: Sea Tower
 - W4G1.msbt: The Great Sea and islands (Spade, Club, Heart, Scuffle, Mushroom, Bonehead, ?, Crescent Moon / Full Moon)
 - W4G2.msbt: Diamond Island, Hall of Trials
 - W5C1.msbt: Spring of Rainbows, Shy Guys Finish Last
 - W5C2.msbt: Spring of Jungle Mist
 - W5C3.msbt: Bowser's Castle, Airship
 - W5G1.msbt: Shangri-Spa
 - W6C1.msbt: Hotfoot Crater
 - W6C2.msbt: Peach's Castle endgame, Origami Castle
 - W7C1.msbt: Sensor Lab, satellite offices, radar tests
 - W7C2.msbt: Cafes