Family Style (Dallas)
Bucca di Beppo - is an Italian restaurant with family style entrees
I have been to workshops held at Maggiano's (also Italian) that served the food family style. Not sure if that is the norm or something special they did for this organization.
I'm not a huge fan of Italian restaurant food so I can't give a valid review of those locations.
The food was as good as any other chain Italian restaurant.
My favorite family style is Celebration Restaurant (near LUV field)- have had family parties there in the past. The sides and salad are family style the entree is single serving. However the entree is all you can eat - you can change your choice too as long as you choose a less expensive entree. So when I go I usually order pot roast and then switch to fried chicken as a second helping. You can probably limit the entree options that people have to choose from if you are looking for cost control. Dh always orders their chicken fried chicken, their fish is good, pot roast is delicious, kid's meals are well liked my my boys.
Good luck with your planning.