The menus you'll find online are accurate to a certain extent. The "finer" restaurants at Disney change their menus fairly often to get the freshest ingredients for their dishes. For example, several things that my family had at Jiko's in January are no longer on the menu you'll find on Deb's site. The menus are kept small for the same reason; they want to have the freshest possible ingredients, so they don't want to have to make huge orders that stay in the fridge forever.
At the Yachtsman, I know, you get a side w/ your meal. You pick between mashed, baked or au gratin potatoes. I can't remember if you could pick some other veggie, but it being Disney, you probably could. On the side dish menu, those sides are family sized, meant for sharing.
When we went in January, there were four of us. Two of us got crab cake appetizer, we all got a steak w/ one form of potato or another, and my DH got the spinach from the side dish menu. We were SO FULL we could barely walk.

We ate hardly any of the spinach. My DD wanted au gratin potatoes, but it was late and they were out. However, the mashed potatoes were some of the best we've ever had. The crab cake appetizer is quite small, and unless you have a small appetite, get your own, don't share.
As for salads, I really don't know. Neither my DD nor I eat salad, and I can't remember if my DH got one at Yachtsman or not.
It is fairly limited, true. But fine restaurants all over the world have small, limited menus b/c they get what's freshest. They don't want to have a bunch of ingredients laying around that aren't going to be at their peak when they cook with them. It's worth having limited choices, because the food you get is SOOO good.
And, hey, you could always get desert.

Or, at the Yachtsman, walk down to Beaches and Cream and get a sundae or something. Yummy!