The king uses this question to show his shock and anger at what Haman was doing. This question can be translated as a statement. AT: "He even dares to attack the queen in my presence and in my own house!" (See: [[rc://en/ta/man/translate/figs-rquestion]])
Speech coming out of the mouth is a metonym that represents speaking. AT: "As soon as the king said this" (See: [[rc://en/ta/man/translate/figs-metonymy]])
Apparently they did this because they understood that the king wanted Haman to be killed. AT: "the servants covered Haman's face as a sign that he would be killed" (See: [[rc://en/ta/man/translate/figs-explicit]] and [[rc://en/ta/man/translate/translate-symaction]])