Tapas comes in three sizes Pincho(bite size), Tapa(snack size) and Racion(plateful). The origin's of tapas is lost in time making way for many theories, but i think the most likely is that the bar owner's just offered a simple easy to make salty snack to encourage drinking and to entice customer's . Competition started and it just spread across the country. Today most tapas are bought in and its not easy to find a tapas bar that prepares it own food. There are a couple of branded tapas bars in the Costa del Sol like Lizarran, which can be found in most town's. The best Tapas bar's are set back from the front and down back street's in the old towns like in Marbella Estepona and Malaga.
Typical tapas click image to enlarge