I previously mentioned attending a Passover Seder with a Messianic Jewish congregation. (Messianic Jews hold to Jewish heritage and traditions, but believe that Jesus was the Messiah). Seder is a specific order with specific foods, readings, blessings, etc.
The Passover Seder Plate (ke'ara) is a special plate containing symbolic foods used by Jews during the Passover Seder. Each of the six items arranged on the plate have special significance to the retelling of the story of the Exodus from Egypt, which is the focus of this ritual meal. (Wikipedia)
The 7th symbolic food is set apart and consists of a stack of 3 whole Matzot. The unleavened bread symbolizes the haste of the preparation of Israel in leaving Egypt; they did not have time to prepare regular bread. The middle matzo is broken into 2 pieces. The larger of the 2 pieces is wrapped in a napkin and set aside. This is the Afikoman and is later eaten at the conclusion of the meal. The Afikoman must be eaten before midnight and once it is eaten no further food or alcohol is consumed.
There are a couple of explanations as to what the stack of 3 Matzot represent. The most common seems to be that they represent Abraham, Isaac (who was 'sacrificed' and returned from the 'dead', and Jacob. The Afikoman represents that which is to come - the Messiah. According to the leader of the Seder we attended, it was the Afikoman that Jesus broke during the Passover meal with his disciples when he said "This is my body".
I don't know with certainty that this is true, but it certainly adds another dimension to the richness of the account of the last supper.