The origin of the word 'sandwich' for an item of food may have originated from a story about John Montagu, the 4th Earl of Sandwich. He didn't really 'invent' the sandwich but he may have made it popular.
It is said that in approx.1762, he asked for meat to be served between slices of bread, to avoid interrupting a gambling game. This story may have been rumour or adverse propaganda, put about by his rivals.
But soon people may have started ordering “the same as Sandwich”, and the name stuck