What does the Benche mean?

Merchant banks are in fact the original "banks". These were invented in the Middle Ages by Italian grain merchants.
Originally intended for the finance of long trading journeys, the methods were later utilized to finance the production of grain.
The merchant's "benches" (bank is a corruption of the Italian for bench, as in a counter) in the great grain markets became centers for holding money against a bill of exchange, later still, a cheque.

Source: Wikipedia.