It is unclear precisely how many Christians there were at this time. There were at least 5,000 men (Acts 4:4). It is unlikely that literally all the disciples gathered together for this meeting since it would have been almost impossible to come and speak to everyone at the same time and come to an orderly decision.
2 And the twelve summoned the full number of the disciples and said, “It is not right that we should give up preaching the word of God to serve tables.