At the banquet, what did Queen Esther finally ask King Xerxes to grant her?

Answer: Her life and her people's

Esther asked for her own life and the lives of her people, for they had been sold to destruction, death and annihilation.

“Queen Esther replied, “If I have found favor in your sight, O king, and if it pleases the king, grant me my life as my petition, and the lives of my people as my request.”— Esther 7:3 (BSB)