sandwich

The card-table story, checked

The popular account has the earl, an inveterate gambler, eating cold meat between slices of bread at the gaming table rather than rising for a meal. The Online Etymology Dictionary hedges it twice over: the word is “said to be” a reference to Montagu, and the anecdote itself dates to 1770 — later than the word's own 1762 record.

So the honest version is: the name link is the etymology both cited dictionaries give, while the gambling scene is a reported origin story, not proof that the earl invented the food or that this meal happened as told.

A place name under the title

The earldom takes its name from Sandwich in Kent, one of the Cinque Ports — Old English Sandwicæ, literally “sandy harbor (or trading center),” per the Online Etymology Dictionary. The same entry records that Captain Cook named the Hawaiian islands for Montagu in 1778, when he was first lord of the Admiralty — which is why a “Sandwicher” could occasionally mean a Hawaiian in 19th-century British usage.

Forms the word picked up

The verb — “insert between two other things,” on the image of meat pressed between bread — is dated 1841 by the Online Etymology Dictionary and 1861 by Merriam-Webster's verb sense; the two dates are kept scoped rather than merged. Open faced sandwich is recorded by 1920, and sandwich board, worn front and back, from 1864.

Club sandwich belongs to the same entry family: Etymonline dates it by 1894, from a dish of chicken or veal with lettuce served to members of The Musicians' Club in New York, with the familiar stacked form described by 1896.