“the disciple whom Jesus loved” =  John’s description of himself (19:26; 20:2; 21:7,20). He identified himself in (21:24) as the author of this book.

John 19:26  When Jesus saw his mother there, and the disciple whom he loved standing near by, he said to his mother, “Dear woman, here is your son,”

John 20:2  So she came running to Simon Peter and the other disciple, the one Jesus loved, and said, “They have taken the Lord out of the tomb, and we don’t know where they have put him!”

John 21:7  Then the disciple whom Jesus loved said to Peter, “It is the Lord!” As soon as Simon Peter heard him say, “It is the Lord,” he wrapped his outer garment around him (for he had taken it off) and jumped into the water.

John 21:20  Peter turned and saw that the disciple whom Jesus loved was following them. (This was the one who had leaned back against Jesus at the supper and had said, “Lord, who is going to betray you?”)

John 21:24  This is the disciple who testifies to these things and who wrote them down. We know that his testimony is true.

The party was reclining around the table on a series of pillows or “couches,” which were basically 3-man pillows. They leaned on their left elbow which freed their right hand to deal with the food and wine. The place of honor was to the left of the host and the second place of honor was to His right. John was reclining to the immediate right of Jesus in the second highest place of honor and Judas was to His left in the highest place of honor, as can be seen by Jesus handing the morsel to Judas and by His talking to Judas (Matt 26:25) without anyone else hearing them. These positions could have come about for two reasons. Either they were a result of the squabble among the disciples before the dinner as to who was the greatest in the kingdom of heaven with a possible fight over who got to sit where, or they were assigned by Jesus. If the first were true, then the character of Judas is even more maligned. If the second were the case, then Jesus was making a grand last appeal to Judas to repent, by giving him the place of the host’s closest friend and thus indicating His love for him.

Matthew 26:25  Then Judas, the one who would betray him, said, “Surely not I, Rabbi?” Jesus answered, “Yes, it is you.”