Be Our Guest is a quick service for both breakfast and lunch. We have done both but prefer the breakfast over the lunch menu. You do need to make a reservation for this even though it is a quick because it fills up quick! The dinner is considered a sit down.
On our last trip we decided to only go with the quick meals (we found it too difficult to race to sit down reservations with kids) and this was definitely the best choice for my family. Even with quicks, we found the meals to be so big! My husband and I actually would share our lunch (use one quick) and then we used the additional quicks that accumulated for breakfast. We also tried saving our snacks for Epcot with the plan to snack around the world... turns out we weren't hungry at all and only used three snacks for a family of four! We ended up using our extra snacks for souvenir treats at the hotel store on our last day.