We were just there last Sunday for a 4:10 and it was the dinner menu. That is interesting the OP has a 3:2(3)5 adr because when we went in at 4:10 the restaurant was essentially empty, sittings starting anew for the dinner crowd. It made me think they must stop lunch sittings pretty early to have place empty like that.
Just to add, when you are there at 4:00 for the beginning of the dinner service, the cms entertain and start the dinner cycle by all singing "O Canada", some in English and some in French. Just kind of fun.
The meals were super by the way. To the OP, you will have a great time!