Here is a great tip from the weekly All Ears newsletter email.
... from Gretchen: If you are making dining reservations and have a baby with you who will not be sitting in a seat or ordering a meal, you still have to include them in the number of people on the reservation. This is due to fire codes and the actual number of people in a restaurant. We showed up at our dining reservation and were told that we could have been turned away if they were full. Luckily they weren't and were able to accommodate us.
What a great tip! I had not even thought about the fire codes before! Keep that in mind when you are making your advanced dining reservations at any Disney restaurant in the parks or resorts!