There is only one file type that uses the .TB extension:
Tabbery Tab File
Configuration file that contains instructions used by Tabbery to launch a virtual tab on the user's desktop; includes the name of each window, as well as each window's screen coordinates, size, and order; also includes bitmap thumbnails for previewing the file contents.
The TB file also stores files such as word processing documents, spreadsheets, audio, video, and photo files in a compressed format.
NOTE: Tabbery is now Slideband.
Updated: June 29, 2011