I remember a man in one of my childhood churches. He had the most distinctive prayers. They were long, but it was also the timbre of his voice, the passion of his requests, his volume in a huge sanctuary. I could have been in Topeka and heard him pray and I would have recognized him.
It had to be the same with Jesus. Having Him sit at your table, break your bread and bless it and then hand it around must have had a distinctive character to it. Even in his walking and talking and teaching they did not recognize Him. It isn't their fault. The Bible says they were kept from recognizing Him. After all, if they had known Him right off the bat, He would not have had the time to give them the wonderful gift of understanding they got.