Is there a file I can edit to add or change the list of names in the name generator?
Kinda. The names aren’t picked from a list, they are generated from a table that lists probabilities of various sequences. If you want to read about the math, search for “Markov Chains”. If you just want to modify the names, take a look here:
You feed that tool a list of names (I find it works best with ~300 names) and it will generate a .ltr file (probability table) which you can then put in override or a hak. The tables are tied to races, so you’ll need to override an existing one. There should be more docs on that page.