How many of the desciples were at the resurrection dinner?

Answer 1

There was not a "Resurrection Dinner", per say. The eleven remaining disciples (sans Judas Iscariot) were gathered, mourning the death of Jesus, in Jerusalem. Jesus is said to have appeared amongst Them. They thought Jesus was a ghost, until He asked for food. He was given a broiled fish. Hardly a dinner, however it is the only time when food was eaten, post-Crucifixion, that was attended by Jesus and The Disciples.

If You are referring to the Last Supper (pre-Crucifixion) there were thirteen men seated at the table; Jesus and all twelve of the male disciples. Bear in mind that there were also female disciples, Mary Magdalene being foremost of Them. However, according to Jewish traditions of the day, the female disciples would not have been seated with them; They would have been there to serve the food.