Everytime one wants to leave his or her memory behind among his beloved people, he grants them or gives them a memento. Jesus' choice of a means of helping us remember Him is a very noble and down-to-earth one: food and drink. He could have very well left us with some stone or wood carving (the cross would have sufficed, normally speaking). But He chose food and drink. For it becomes part of us. It does not remain an external reminder to the eyes or ears alone, but merges with our system and strengthens us from within.
Another aspect of this 'memory tool' is the specialty that it builds us up ... from within. It is not something that we can pass on to others without ourselves being strengthened by it. Every and any of my acts is supported by food and drink. Furthermore, no credit is given to this factor. Food is consumed and the credit of the good done is given solely to the doer; not to what he or she eats and drinks.