Midrasch zu Tehillim 69:23

(Ib. 45) And Esther said, Let the king and Haman come this day unto the banquet. Our Rabbis were taught: For what purpose did Esther invite Haman to the feast? R. Elazar said: "She spread for him a net, as it is said (Pr. 69, 23) May their table become a snare before them." R. Joshua said: "She learned it in her father's house, as it is said (Prov. 25, 21) If thy enemy be hungry, give him bread." R. Meier said: "So that Haman should not learn of the matter and cause a revolution." R. Juda said: "So that it should not be noticed she was a Jewess." R. Nechemia said: "So that the Israelites say not, We have a sister in the king's court, and they should not [meanwhile] dismiss from their minds the idea of praying for mercy." And R. Jose said: "So that he should be near, if she wanted him." R. Simon b. Menassia said: "So that He above should notice [how she was forced to flatter her enemy] and should perform a miracle." R. Joshua b. Karcha said: "She intended to make herself agreeable to Haman, so that the king might become jealous, and should kill both him and her [whereby Israel would be saved]."