Mir Talmid is correct. Shalosh Seudos is eaten at a special time- hence many sing zemiros/ say Divrei Torah at length during this seuda.
I have been told that, as he said, it brings all 3 seudos together. By eating this meal, we get s’char for eating all 3 Shabbos seudos.
At the first two seudos we may arguably have been eating to satisfy our hunger and our desire for the delicious food. By the time we get to Shalosh Seudos, we’re not hungry and probably don’t feel like we want to wash and eat another piece of Challa. But we do anyway, in honor of Shabbos! And by doing so we prove that we were eating the first two meals also L’Chovod Shabbos.
Yes, Wolf, may Heaven help us all to merit the enjoyment of “Shalashudis”!
😉