Paten

Paten, 13th century, now part of the Metropolitan Museum of Art Ensemble for the celebration of the Eucharist
Derrynaflan Paten, part of an 8th- or 9th-century communion set found in County Tipperary, Ireland

A paten or diskos is a small plate used for the celebration of the Eucharist (as in a mass). It is generally used during the liturgy itself, while the reserved sacraments are stored in the tabernacle in a ciborium.