We took our daughter at 14 months and she had a great time! She really enjoyed the princess breakfast at Akershus in Norway, and Chef Mickeys and Crystal Palace are both great character meals. I'd also recommend Garden Grill in the Land pavilion at Epcot as another good character meal (Chip & Dale, Mickey, and Pluto - I think).
As for non-character meals, Ohana for dinner is great. I'd also recommend one of the World Showcase restaurants for watching Illuminations if you can handle a later dinner. Rose & Crown or La Hacienda both offer great views of the show. Coral Reef can be fun for the kids as they can watch the fish up close, but the food is very hit or miss. Chefs de France lunch with Remy was also fun.
If your son really likes dinosaurs you might try T-Rex at DTD, although we personally avoid it and Rainforest Cafe for very young kids - both were very loud and "touristy" in our experience, but others love them.