Ah, I see. I didn't connect buffet with "table service" since you have to serve yourself!Yeah sorry we consider a sit down meal a meal where you have to make a reservation and usually have a server come to your table or a buffet. We call the other style quick service because that’s what they call it at Disney world
I'd also consider Ristorante di Caneletto at DS, especially on the balcony as there will be stuff for the little one to "watch". You could even try to overlap eating with the daytime harbour show (although the view is probably better from the quick service pizza and pasta place balcony (which fills up hours in advance)).
From the other table service restaurants ... Crystal Buffet is probably a good choice with a little one. Maybe Blue Bayou if you get a table near the water, but it's very dark and the menu is very ... fine cuisine. We had trouble finding options to eat. Magellan's, the big cruise ship in DS, etc probably aren't great choices with a little one. We haven't eaten at the two table service Japanese restaurants.