In the Catholic Church, Holy Thursday, is the first day of the Triduum, the three days during which we commemorate Christ's Passion.
When Jesus and his disciples ate the Last Supper, it was on the first night of the Passover festival, otherwise known as the Seder meal.
This is the night that Judas betrays Jesus.
Mark 14:16
And his disciples went forth, and came into the city, and found as he had said unto them: and they made ready the passover.
And in the evening he cometh with the twelve.
And as they did eat, Jesus took bread, and blessed, and brake it, and gave to them, and said, Take, eat: this is my body.
And he took the cup, and when he had given thanks, he gave it to them: and they all drank of it.
And he said unto them, This is my blood of the new testament, which is shed for many.
After the feast, Jesus washes the feet of his disciples as an example of humility.
A symbolic Seder meal would have consisted of many things. This is similar to what Jesus ate at the Last Supper.
Zeroah traditionally a piece of roasted lamb shank bone, symbolizing the paschal sacrificial offering
Unleavened bread (Matzoh) called "bread of affliction" because it recalls the unleavened bread prepared for the hasty flight by night from Egypt. Three large matzohs are broken and consumed during the ceremony.
Beitzah: a roasted egg, as a symbol of life and the perpetuation of existence.
Bitter herbs (Moror) is a reminder of the bitterness of slavery and suffering in Egypt.
Karpas a vegetable, preferably parsley or celery, representing hope and redemption; served with a bowl of salted water to represent the tears shed.
Charoses represents the mortar used by Jews in building palaces and pyramids of Egypt during their slavery. (It is a mixture of chopped apples, nuts, cinnamon and wine.)
Wine is dipped from a common bowl. The 'Four Cups,' Thanksgiving, Hagadah ('telling'), Blessing, and Melchisedek ('righteousness'), are "four different words for redemption, spoken by God to Moses."
Peace be with you.