Comentario sobre Ester 5:4

Let his majesty and Haman attend. Our Rabbis listed many reasons for the matter.⁴Ibid. What did Esther see [i.e., what motivated her] to invite Haman? In order to make the king and the princes jealous of him, [or], so that the king should think that he desired her and kill him; and many other reasons.⁵Another reason given is that she felt that the Jews would rely on her influence with the king rather than on G. She therefore created the impression that she abandoned them in favor of Haman, so that they would concentrate fully on prayer and penitence. (Megillah 15b)

At the feast. Every feast is called מִשְׁתֶּה on account of the wine, which is the principal feature.