In order to correct some of the disorders that had crept into the worship of the saints at Corinth, the apostle tells them to deal with their hunger at home. Apparently, the love feast that accompanied the Eucharist in the first century was being used as an occasion to fill the belly, at the expense of others, rather than to nourish soul corporately and covenantally. And to all such, the apostle says that physical hunger should be fixed at home.
This is a spiritual meal. But by this, we do not mean that it is an ethereal meal – the bread is true bread, and the wine is true wine. But at the same time, it is a meal that is also consumed in the heavens, where we are seated with the Lord Jesus Christ. He descends in the person of the Holy Spirit to be with us here, in our particular town. But we ascend to Him in that same Spirit so that we might eat heavenly bread and drink heavenly wine by faith. This happens regardless of the amount of bread or wine we have here. Too little would lead us astray, and we would begin to think that “heavenly” means “vaporous.” Too much would lead us astray, as it did our Corinthian brothers and sisters, to the point where they became belly-gods, making a idol of the digestive system.
So be more concerned for the size of your faith, than the size of the loaf or cup.