Descriptions of the data types used here:
There are a few ways to find the end of a string. Here are three of them:
(1) Check the offset of the next string to find how much longer it is than the current one. This is probably the quickest way to do it and usually finds the correct length of the string, but it will not work with certain .tbl files.
(2) Check the offsets of every string. This method is the slowest one, but will always find the correct length.
(3) Look for a null character to signal the end of the string. I think this is the way Blizzard games do it, but it probably would not be the best way to do it for a .tbl file editor.