There is only one file type that uses the .TLK extension:
BioWare Aurora Engine Talk Table File
Language dialog file used by BioWare first-person shooter games; contains strings of dialog that are displayed during gameplay and allows the game to have multiple localizations for different languages; supported by BioWare's Aurora Engine and Infinity Engine technologies.
TLK files are often named dialog.tlk and are located within the game installation directory.
NOTE: Example games that use TLK files are Neverwinter Nights and Star Wars: Knights of the Old Republic (KotOR).
Updated: May 17, 2012