What's interesting is that "The Earl of Sandwich" was just a title like "The Earl of Devon", "The Earl of Suffolk", "The Earl of Essex", etc.

Sandwiches got their name because that Earl liked playing cards and wanted food he could hold that wouldn't mess up his cards. So, it's like calling one of the things he (or his cook) invented "A McDonalds". But, now, we're so used to the name "A Sandwich" that the title "Earl of Sandwich" sounds weird. Even though "wich" is a pretty common place name ending, like "Norwich", "Dunwich", etc. And, "Sand" is pretty normal as part of a place name, but not as part of food.