The Passover meal is eaten during the festival of the unleavened bread when the Passover lamb is Sacrificed. ( where did God say this should be done yearly why?)

Jesus knew what Judas was about to betray Him, yet Judas was at the table. Jesus knew what  His purpose was. The purpose of coming to earth was about to be fulfilled. HE was aware of what laid ahead of Him. There was no animosity in Jesus' dealings with Judas. He rather repaid good with the evil Judas was about to do. Judas was part of the meal.