I apologize if this has already been answered previously but I searched the threads and had no luck finding an answer. That being said, I can't seem to get the map editor to work on my Mac (10.6.8). The file is a .exe, I'm not sure what I'm supposed to do with it if anything.

On a totally random note, I'm so happy that this game exists! Takes me back, I thought I would never play it again.

If anyone can help, thank you!

Sorry but unfortunately there is no map editor for mac. You can check out tauniverse for maps though.
You could also check out my mappack: http://www.tauniverse.com/forum/showthread.php?t=43725

The map editor is present in the game files, but might not be easily accessed because on the Mac version, the game runs in WINE. However, it's feasible that WINE could also be used to point to the map editor. Sometimes windowed applications like that can have difficulty under WINE, though.

I love editing for TA on my PC, so perhaps I'll look into it and see if there's a way to make a working wrapper (as WINE calls them) that will run either the official Total Annihilation Editor or "Annihilator", my favorite Windows TA mapping program (it's a lot more stable, too).