In Roman Era dwellings, particularly wealthy ones, triclinia were common. Used to entertain company, the hosts and guest would recline on pillows while feasting on the flesh of lesser beasts and other refreshments. For an example of an accurately reconstructed triclinium, visit the Museum of Archeology in Arezzo, Italy, or the House of Caro in Pompeii.
Dining was the defining ritual in Roman domestic life, lasting from late afternoon through late at night. Typically, 9-20 guests were invited, arranged in a prescribed seating order to emphasize divisions in status and relative closeness to the dominus. As static, privileged space, dining rooms received extremely elaborate decoration, with complex perspective scenes and central paintings (or, here, mosaics). Dionysus, Venus, and still lifes of food were popular, for obvious reasons. Middle class and elite Roman houses usually had at least two triclinia; it's not unusual to find four or more. Here, the triclinium maius (big dining room) would be used for larger dinner parties, which would typically include many clients of the owner.
Smaller triclinia would be used for smaller dinner parties, with a more exclusive set of guests. Hence their decoration was often at least as elaborate as that found in larger triclinia. As in the larger triclinia, wine, food, and love were always popular themes. However, because of their association with patronage and because dining entertainment often including recitation of high-brow literature like epic, dining rooms could also feature more "serious" themes, as in this instance the wounding of Aeneas from the Aeneid. As in many houses in Pompeii, here the smaller dining room (triclinium minus) forms a suite with the adjoining cubiculum and bath. The triclinium, or dining room, took its name from the three couches called klinai, on which family members and their guests lounged to take their meals. Each couch was wide enough to accommodate three diners who reclined on their left side on cushions while some household slaves served multiple courses rushed out of the culina, or kitchen and others entertained guests with music, song or dance.