From the magnificent Cedar Room blog:
There’s a temptation to hear “Last Supper” and merely think it was the last meal of Christ before he died. The “Last Supper” is actually the final supper of all mankind; it is the meal which man will always eat, the final meal, the eternal meal. It is not the “last” because it is followed by no more suppers. It is “last” because it is never replaced by any greater supper. The “Last Supper” is the reason we have teeth, tongue and stomach.