A VERY informal way to say "che noia" (to express boredom), or to express annoyance. Though it's considered to be rude by some, I'd recommend using it only with close friends, as it is intended to be. Never use it in workplaces or academic contexts.
A few examples:
[Waiting in a queue] "Che palle questa fila!"
[A friend pokes you and it's being intrusive] "E che palle!"
[Out of boredom, proposing to do something] "Che palle, facciamo qualcosa"