Imperial Pilot: What do you think about the new Tie fighter?
Palpatine: Flew it.
Imperial Pilot: What do you think about the new Tie fighter?
Palpatine: Flew it.
Listen up, buttercup. The joke here is that the pilot is asking Palpatine his opinion of the new Tie fighter. Palpatine, being a Sith Lord and all, gives a short, vague response: "Flew it." It's funny 'cause he's basically saying he's flown it before, implying he doesn't need to give a review or any more detail, because he's HIM. Get it? You wouldn't.