means benches (Anglo-Saxon, scamel; Latin, scamnum, and the diminutive scamellum, a little bench). The benches or banks on which meat is exposed for sale. (See Bank.)
“Whatsoever is sold in the shambles, that eat, asking no question.” —1 Cor. x. 25.
Source: Dictionary of Phrase and Fable, E. Cobham Brewer, 1894