Who is eating with Jesus in the Last Supper?

12 men

These were the 12 disciples who were his closest followers.

They were:

Simon (whom Jesus nicknamed 'Peter' the 'Rock')

Andrew, brother of Simon/Peter

Both of these were fishermen.

James and his brother John, the sons of Zebedee

These were teenage boys and Zebedee their father was also a fisherman, so it is assumed that they would have followed on in his profession.

Matthew, (also called 'Levi') was a tax collector

The rest of the disciples were:

James, the son of Alpheus

Philip,

Bartholomew (also called 'Nathaniel')

Thomas (also called 'didymus' - 'the twin')

Thaddeus, also called 'Judas' or 'Jude'

Simon the Zealot, and

Judas Iscariot. (who betrayed Jesus). After his suicide, Matthias took his place, but Matthias wasn't at the Last Supper as he did not become a disciple until after Jesus' death and resurrection.

We are not told the professions/occupations of these disciples.