The Scene
John didn't miss the significance of the miracle. A mysterious man on the shore had told them where to cast their net, and the catch was amazing. John knew, it was the Lord standing there on the shore!
This was clearly an emotional moment -- especially for Peter, who immediately cast himself into the sea in order to get to Him quicker, even though the boat was "not far from the land" by John's count (who opted to take the boat instead.)
Peter and Jesus had a moment together before the boat arrived with the catch. In light of their history together, this was no doubt a precious moment for Peter. (See Michael Card's excellent book on Peter for a great exegetical picture of their friendship.)
The Meal
When the other disciples hit land, there was already a fire gong with some fish on the grill, and bread too. Clearly Peter did not bring the food, and it is very unlikely that he went to go get it during this brief interval. So, Jesus set this up (whether miraculously or not we do not know.)
Jesus tells them to bring some of the fish they caught. We will see why in a moment.
Peter went to help bring the net in before dining. The mention of "153" large fish is simply part of a sentence intended to remind the reader of the miracle; that "although there were so many, the net was not torn."
Jesus invites them to eat, and begins to serve them food.
The Significance
The Lord has met these tired fishermen with a fire, food, and fellowship, and then proceeds to serve them. We have already seen the love, provision, and devotion of Jesus prior to His crucifixion. John is now showing us His same love, provision, and devotion after His resurrection.
Jesus does not simply feed them, as He had in the past. What we have here is a group of friends coming together to eat. Yes, He had provided their fish miraculously, but they also worked for it; He enabled them to bring something to the table as well. And then He served them. John is showing us the partnership and fellowship that Jesus had with His disciples after His resurrection.
Fish and bread were common foodstuffs in their day. Jesus is providing the food they are accustomed to eating (just as He spoke the language they were familiar with, and met them in the place they were accustomed to fishing at.) The significance here is that the Lord went to their world -- in more than one way.