The triclinium

A fresco of a triclinium in Pompeii. From historyforkids.com

Roman diners were accommodated on couches arranged in a ¨U¨ shape and called the triclinium. When the guests were seated, their slippers were removed. If the host was rich or pretentious, his guests might then be subjected to a full-scale pedicure, although it was more usual for slaves simply to bring round ewers of water so that they might wash their hands and bathe the dust of the street from their feet.

A reproduction of a triclinium. From wikipedia.org

Triclinium. From novaroma.org

The table was set in the centre of the ¨U¨ and, as the courses came and went, ¨a high-girt slave with purple napkin wiped well the maple-wood table, while a second swept up the scraps and anything that could offend the guests¨. This last, slightly sinister phrase (from one of Horace´s Satires) takes on meaning when it is realized that Roman wall hangings and canopies occasionally came adrift, descending ¨in mighty ruin upon the platter, trailing more black dust than the north wind raises on Campanian plains¨. When this happened, guests were inclined to call for their slippers -a sign that they intended instant departure.

REFERENCE. 

The Fine Art of Food. By Reay Tannahill. P. 19