I could imagine that times then were hard and food somewhat scarce. A whole loaf of bread divided equally would be a small meal and a bottle of wine could serve well to wash down the bread. I could not imagine that Jesus would only give a tiny peace of cracker and a thimble of grape juice.
It would have actually been a pretty lavish meal. It was Pesach. That means it was the "seder" for Passover, the communal dinner to celebrate that Feast day. It is the only feast day that is celebrated, to this day, at home. That is, in someone's home or homelike setting. A Passover Seder is one of the primary Feasts (MoAdim) Moshe (Moses) laid out in the Torah, that is the first 5 books of what is now called the Old Testament scriptures (of the Jews, Messianics and Christians).
Jews (remember, Jesus was a Jew and was then still in complete obedience to the Mosaic law) saved up all year, and many still do, for that feast meal. Family came from all around, even other lands, and it was one of 3 "pilgrim" feast days in that the adult males had to go to Jerusalem to observe, if they could. That's why Jesus had someone go and find the man who had "prepared" for them "the meal." Passover is always done with matzah and wine. Matzah is just the hebrew word for unleavened bread. Y'shua (Jesus) served that day and the next as "'the Lamb of God" who takes away the sins of the world,'" just as John the Baptizer said of him, and also as the First Fruits (of the New Covenant). See Hebrews 13:11-16:
The high priest carries the blood of animals into the Most Holy Place as a sin offering, but the bodies are burned outside the camp. 12 And so Jesus also suffered outside the city gate to make the people holy through his own blood. 13 Let us, then, go to him outside the camp, bearing the disgrace he bore. 14 For here we do not have an enduring city, but we are looking for the city that is to come. 15 Through Jesus, therefore, let us continually offer to God a sacrifice of praise—the fruit of lips that openly profess his name. 16 And do not forget to do good and to share with others, for with such sacrifices God is pleased.
The amount of bread and wine that Jesus used at the Last Supper communion would not have been a great quantity.
22 And as they were eating, he took bread, and when he had blessed, he brake it, and gave to them, and said, Take ye: this is my body. 23 And he took a cup, and when he had given thanks, he gave to them: and they all drank of it. 24 And he said unto them, This is my blood of the covenant, which is poured out for many. - Mark 14:22-24
Some translations say a loaf [of bread].
Seeing that Jesus did this during the course of the Passover Feast, the need for a large quantity of bread or wine would not have been necessary. It could also be noted that Jesus took the cup (singular) and not cups of wine demonstrating that the quantities of both would not have been great. It was probably one [loaf of] bread and one cup of wine. The symbolism of this gesture is quite profound.
The actual Passover Feast or Pasch that was also celebrated that day would have been a different story altogether. The size of [the loaf of] bread used by Jesus in the post Pasch communion of the gospels is not known to us.
Quite a lot
They're having a meal together. So all must have eaten till they are full of bread and drink.
What do we expect? That they have "communion" and after that all of them go their separate way for extra meals at local KFC equivalent?
In fact, communion in the beginning must be quite a lot too.
Paul complain that some are full and drunk. The rest don't get any. So yea the wine must be alcoholic too.
Currently christians use grape juice and a tiny winiy bread. So much for "real" experience of communion.