“Tapas” is that small dish very common in Spain. Usually “tapas” are eaten standing in a bar, and you order them together with your wine or beer.
The origin is quite unknown but there is an anecdote of the King Alfonso XIII (1886-1941) when he was travelling to Cadiz. The King decided to stop in a beach restaurant.
The King Alfonso XIII ordered a cup of Sherry wine, but did not realize about the wind outside that was coming into the restaurant, and could mess with beach sand his wine cup. A clever waiter had the idea of covering (“tapar” in Spanish) the wine cup with a ham slice.
When the King was going to drink it, he asked: “what is this?”. The waiter answered: “Sorry, My King, I just put a tapa for not to dirty your wine” . The the King ordered for another wine cup but he said to be covered again with the same tapa. Everybody start to laugh and ordered the same than the King.