We aren't a "buffet with kids" family. But the Biergarten buffet was very enjoyable and if you don't mind getting your own food (and your kids food, and then more food for your kids and then, oh, my, my food is cold....see why we aren't buffet with kids people) it was a really good buffet and the restaurant is certainly child appropriate. You may share a table here with strangers.
You may also share a "table" - actually a grill - at Teppenyaki. We really enjoyed it here and had a wonderful time, but the grill is hot and nervous people with fidgety toddlers may have less than a great time (they put both ours on the ends, where the grill is cooler - but that meant I had a hard time helping them).
Le Cellier is a great restaurant - excellent food - rather quiet and subdued for a park restaurant and for my preference with kids. But they do serve the Chocolate Moose for dessert - my kids still talk about that.
Marrakesh has been a long time favorite of ours. Our daughter particularly enjoys the belly dancer. Try for a table close to the floor - your DD can join the dancer. A little quieter than some other choices.
We love San Angel Inn, too. And our kids did fine there at 2 1/2 and 3 1/2. Its a little dark. Try for an earlier PS and try and get a table by the water. Also, while you wait for food, someone can ride that awful boat ride with her. Almost never a line.
Not an Epcot restaurant, but Spoodles is basically out the back door of Epcot (as is Beaches and Cream). Everyone but me really enjoyed their meal at Spoodles. Haven't been to B&C, but a lot of people love it.