This secret receptacle, mounted on the back of a table or chair, can be seen as an evolution of the street magician's Gibecière or Budget (an apron with pockets). This development seems likely to have occurred when magicians began to perform more frequently off the street, in taverns, rooms and on stages, where conditions could be better controlled and audiences could be prevented from wandering behind the performer. A clear transition from Gibecière to Servante can be seen in the work of the eighteenth-century French professional, Conus the elder, who, according to Robert-Houdin, devised the simple yet clever idea of pinning up the rear edge of a tablecloth to form a secret pocket as an aid in his Cups and Balls routine; see Robert-Houdini's Les Secrets de la Prestidigitation et de la Magie (1868), English translation by Prof. Hoffmann, The Secrets of Conjuring & Magic (1878, p. 342).
The far less spontaneous rigid shelf or bag, attached to the table, appeared by the first half of the nineteenth century. Robert-Houdin described them in the book cited above (pp. 66 and 284), by which time they seem to have become standard tools for conjurers.
See also: Body Servante