Annotations by Edward Hawkins on the British Museum impression identify the man on the left as Sir W. Inglesby and the seated man to the right of the table as Lord de Roos. The former is Sir William Inglesby M.P., while tha latter is Henry William FitzGerald-de Ros, 21st Baron de Ros (1793–1839), who "was an excellent whist player, but was involved in a gambling scandal in 1836. Lord de Ros was accused of cheating at Graham's Club by the trick of sauter la coupe, and by marking the cards with his thumbnail. He sued his accusers for libel, but lost the case. He died not long after" (Wikipedia). The "Legerdemain" in the lettering refers to the conjuring book Ingleby's Whole art of legerdemain, by Thomas Ingleby, 1815