lua and luac (presumably lua compressed) might well be the programming language Lua (though it can be in an odd bytecode format for consoles vs finding the same on PC).
If that is the case then investigate that -- normally if you can't easily determine the font and format thereof then you get to do some quite intensive hacking to figure out how the program handles it. If instead the game will both tell you what files and how it reads them in one of the easiest programming languages people actually want to use then call that a very nice win for you.