where the banquet of wine had been

"where they had been drinking wine" or "where the banquet had been." They were probably also eating food, not only drinking wine.

couch

a long piece of furniture where a person can sit or lie down

"He even dares to attack the queen in my presence and in my own house!"

"attack the queen." This phrase is a polite way to refer to rape.

"As soon as the king said this"

"the servants covered Haman's face as a sign that he would be killed"