The Pala d'oro, or retable of the high altar, is one of the chief glories of St Mark's.
Retable, a shortened form derived from Med.
The foreign "retable" is, therefore, what should in English be called a "reredos" (q.v.), though that is not in modern usage a movable feature.
The gorgeous Pala d'oro, still in St Mark's at Venice, a gold retable covered with delicate reliefs and enriched with enamels and jewels, was the work of Byzantine artists during the 11th century.
The description of the gold and silver retable given to the high altar of Ely by Abbot Theodwin in the 11th century, shows it to have been a large and elaborate piece of work decorated with many reliefs and figures in the round.
As to the question of "altar lights," however, it must be borne in mind that these were not placed upon the altar, or on a retable behind it, until the 12th century.