My record is 65. If I recall I made six recipes of lasagna and had one left over.
I make a regular "serves 12" recipe, bake it in 10 x 15 dishes, and cut it into 15 portions. A couple people have seconds, so "serves 12" works out.
If I were you I would make at least 5 such recipes of each lasagna, maybe six--you can freeze the leftovers after baking even if it was frozen before baking.
For the salads, perhaps you can have them prepped so that you can toss them one bowl at a time, especially the green salad. That way it won't wilt, and leftovers can be salvaged.
Garlic bread is cheap so bring tons of it. At least 5 or 6 loaves. Hopefully you can bake them as you go.
Meatballs: The sky's the limit, they'll eat them till they're gone. Sorry. I would make 200.
I hope that helps, and I hope it is understood that you plan to bring home any food that was not served!