Albert Barnes Commentary Esther 1:5

"And when these days were fulfilled, the king made a feast unto all the people that were present in Shushan the palace, both great and small, seven days, in the court of the garden of the king`s palace." — Esther 1:5 (ASV)

Feasts on this extensive scale were not unusual in the East. Cyrus is said on one occasion to have feasted “all the Persians.” Even ordinarily, the later Persian monarchs entertained 15,000 persons at their table.