A long white cloth that covers the top of the altar. It typically hangs down some distance over the ends of the altar. The BCP directs that at the eucharist the altar "is spread with a clean white cloth during the celebration" (p. 406). Historically, in the early church, a small table was brought out and put in place for the liturgy of the table. A white cloth was spread on the table at this time. As late as the eighth century, a white cloth was spread upon the holy table during the eucharist by deacons after the liturgy of the word. It is appropriate for the altar cloth to be spread on the altar before the service or at the offertory. It may be embroidered with five crosses, one on each corner and one in the center. References to the fair linen date from the 1552 BCP.
Glossary definitions provided courtesy of Church Publishing Incorporated, New York, NY,(All Rights reserved) from "An Episcopal Dictionary of the Church, A User Friendly Reference for Episcopalians," Don S. Armentrout and Robert Boak Slocum, editors.