Table files map characters to other characters. For example:
*00 80=A 81=B 82=C 83=D
... and so on. This means that in the ROM, the byte value 00 indicates a newline, the value 80 indicates the letter A, the value 81 indicates the letter B, and so on. All numbers are hexadecimal.
They are useful for a number of purposes, including extracting a script, inserting a script, reading text in a hex editor, and so on. Unfortunately, tools often have slight variations in the format. For instance if we need a TBL file for an Atlas script, we would start it with 00=<line> instead, but the rest would be the same.