If you find out something of interest about a 2da that's not in this list, by all means, do add it!
A substantial number of them appear to be unused and not all of the ones that appear to be in use have a known purpose. Not all of the game's 2das are included in the following list.
The following list is going to be rather long and not all listed 2das are equally interesting, so here's a small hand-picked selection of 2das every modder should look at at least once: Main article: 2DA Files Most Important 2DAs
