It is historically very uncertain if the accounts of the last supper actually go back to the Historical Jesus or if they are later constructions of the church. My own inclination is that Jesus did celebrate a "last supper" with some of his followers. I doubt he said the "words of the institution," but I suspect he asked them to "remember him while they ate and drank." But perhaps not even that is historical. There is something more important about this meal.
In standard Christian theology Holy Communion is deeply connected with Jesus "dying for the sins of the world." I'm not very interested in that theology. Jesus' death is very important. He was put to death by an Empire and a leadership that despised everything he stood for to make an example to would be rebels. That death is, in many ways, a profound conclusion to his life and mission. But I don't believe in vicarious sacrifice or magic rituals, so the "dying for our sins" part does not move me. I am, however, deeply moved by the ritual of Holy Communion.
Communion reminds as that we are all one, like cells of one body, and that we were meant for "life together" in Boenhoffer's phrase. It is also a reminder that God is intimately near to us, as near as the bread and wine we digest. But there is more to the ritual even than that. Eating together was a (perhaps the) central element in the ministry of the historical Jesus.
Historians and New Testament scholars are unanimous in recognizing an "all-inclusive table fellowship" or "open commensality" as a central practice of the ministry of Jesus. In the ancient world who you ate or did not eat with mattered very greatly. Table Fellowship was a microcosm of the lager society, you did not eat with the the "lower people" or "outcasts."
Jesus directly challenged this ancient table practice with his own. Jesus dined with all manner of people, rich and poor, righteous and sinner, outcast and respectable soul, tax-collect and harlot, P and scribe. For Jesus, all set together to dine as equals. Jesus, from all accounts, appears to have been principally concerned with undoing the divisions of society. His ministry of eating and healing appears to have been designed to radically transform human relationships from exclusive to inclusive, from hierarchical to egalitarian.
The practice of all eating together as equals was the realization of Jesus' vision. In having all dine together as equals, Jesus was not merely proclaiming, but actually destroying the boundaries that divide. No one was to be an "outcast" any longer.
It all probability that is what communion grew out of - Jesus' mission to unite us all; to break apart the divisions which cause strife between us.
So if you take communion tonight or anytime this Holy Week do indeed remember Jesus. But forget theological claims about his divinity or sacrificial death (I suspect that the Historical Jesus would have found such claims a profound waste of time) try to remember his mission to unite, heal, reconcile, and bring together.
In a world still so divided and marred by the violence of those divisions, perhaps it would be good to remember Jesus' call to unity and to try to live it a little.