According to doctrine, it's more than symbolic: Catholicism teaches that bread and wine 'really' turn into flesh and blood, while only 'superficially' maintaining the appearance of bread and wine (cf Aristotle's substance theory and the difference between essential and accidental properties). So under a certain point of view, the Eucharist could indeed be considered cannibalism - however, the body of Christ is divine and cannot be digested...

Yes, with the minor complication that a substantial number of Catholics don't actually understand how it's supposed to work (spiritually speaking) and would be absolutely dumbfounded at the basic concept of transubstantiation.