DH and I split many of our meals last month while at Disney World because we were both still recovering from a bad virus/sinus infection thing and we had lost our appetites (which is a very unusual thing for us! LOL).
Anyway, we shared our meals at these restaurants:
Kona Cafe for lunch
Kona Cafe for dinner
50's Prime Time for dinner
Sci-Fi for lunch
Liberty Tree Tavern for lunch
Cinderella's Castle for dinner
The servers were great, not a smirk or strange look from any of them. They all brought us an extra clean plate to use. And at the Sci-Fi, they even cut our sandwich in half while still in the kitchen and gave us each fries, lettuce and tomato on both plates, so we didn't have to split anything ourself at our table.
We didn't split our meals at Biergarten (because it's a buffet), 'Ohana (because it's all you care to eat), Teppanyaki (because the chef prepares the meal for each person separately in front of you), or at Whispering Canyon (because we each wanted something different).
And we tipped as if we had both ordered a separate entree'.