The service plate is the largest plate. Service plates range in size from 11 to 14 inches across.
The service plate is laid in the center of the cover before the diners come to the table, but the way it is used is different for formal and informal dining. At a formal table, the service plate decorates the cover and the rim should frame the appetizer plate with a surround of no less than one inch.
In formal dining, food is never placed directly on a service plate. Rather, the service plate is a base on which to lay the plate for the appetizer course and is cleared from the table after the first or second course is finished. Since soup splatters, the service plate is soiled easily, and at the end of the course it is cleared from the table with the soup plate. Because there should never be an empty space before a guest, after the service plate and soup plate are cleared, the plate for the next course is laid on the table immediately. But when the meal begins with a cold first course, such as fish, followed by a hot course of soup, the fish plate is removed at the end of the first course, and the service plate is left on the table to hold the soup plate. At the end of the soup course, the service plate and soup plate are cleared together, and exchanged immediately for the plate on which the next course is served.
At an informal meal, the service plate is an optional accoutrement of dining. Although traditionally the purpose of the service plate is to hold the plate for the appetizer course, at an informal meal it is used in whatever way makes sense, as a dinner plate, buffet plate, placemat, or platter. When it is used in the traditional sense, it is laid on the table in advance of seating and should set the mood for the occasion. Oftentimes, dinner plates are used as service plates to hold a first course.
Service plates are known by a host of names - buffet plate, charger plate, cover plate, lay plate, and place plate.
