Passover is celebrated around April. As with many Jewish festivals it starts with a spring clean for the house, everything must be perfect and all of the yeast (used to make bread rise)is removed. Yeast (or leaven as it is sometimes called) is not allowed in the house during the festival. When the Israelites were lead out of Egypt by Moses all the food that they could carry was unleavened bread. This festival has a lot to do with the memories of that time in Jewish history.
Passover is a festival to celebrate the way G*d provided for them when he sent Moses to lead them out of Egypt. G*d freed them from slavery, provided for them on the long journey, provided a home for them and laws for them to live by (the ten commandments). This whole story is told year in and year out at Passover and that has been so for about three thousand years.
One of the main features of the Passover festival is the Seder meal when the story is told. Everything is said and done in the proper order called the Haggadah. Food is placed on the Seder plate to remind them of the time in the desert. These are the special symbols for Passover:-
A Lamb Bone, this is usually a shank bone. It reminds Jews of the lamb that was killed to mark the doorways so that the people living in those houses would be spared when the Angel of Death passed over the home.
An Egg: is a symbol of new life. (because in England the festival is often near Easter, painted eggs or decorated eggs that Christians might use for Easter are also used to represent new life in the Passover festival.
Karpas or green vegetables: This is lettuce or sometimes parsley, it is dipped into salt water and eaten to remember that G*d provided for them in the wilderness. It is a symbol of new life in as much as it reminds them of green fields with crops growing in them.
Maror or bitter herbs: Very often horse-radish, bitter to remind them of the bitterness of slavery.
A fruit, nut, wine and spice mixture called charoset: symbolic of freedom, sweet, pleasant flavours and smells.
There is always salt water and wine on the Seder table. Wine is drunk for the blessing at least four times during the meal. Once to remind them of G*d's promise to provide, once to remind them of G*d's promise to free them, once to remind them of G*d's promise to give them a land of their own and finally to remind them of his promise to take them as his chosen people. The karpas and maybe the egg is dipped into the salt water before being eaten. Salt water is symbolic of the tears shed by the Jews as slaves.
Jesus' Last Supper was actually the Jewish Seder meal that was being celebrated by Jesus and his disciples as they were all Jews. Consequently the Jewish Passover festival and the Christian Easter festival fall very close together. The Jewish festival is worked out on a Jewish calendar and Easter is worked out from a lunar calendar.