2: Correct, but awkward.
3: Correct, especially in spoken English. "Restaurant" is acting as an adjective, describing the menu.
6: Incorrect. This asks something like, "what name are you called at school".
Why is 3 okay but not 6? I guess because most menus are from restaurants, it has become a set phrase. However, lots of things have names, so "school" isn't bound to it in the same way.