勘弁して / 勘弁してよ! / 勘弁してくれ! / 勘弁してください I'm pretty sure that a certain book about English conversation that I've read recently says "Gimme break" means "勘弁して". Btw the books is written by Japanese-American, so I think 勘弁して has a same nuance as "give me a break!".

"Give me a break." is used in various situations, so there are possible expressions used in different situations. 「勘弁してよ。」 or「勘弁してくれ。」 "Kanben shiteyo." or "Kanben shitekure." (lit: Please forgive me. ) This expression is used when someone bothers you by misbehaving or demanding too much. You are tired of taking care or even listening to him/her, and want to be released. Like, kid : Mom, I peed in my pants... Mom : Not again! 勘弁してよ～ 「うそ！」　 "Uso!" (lit: Lie! ) It's simply used when you heard something hard to believe. I think I can give you more exact answer If you could give me the specific situation.

When I want to ask someone if I can take a break, I would say : 少し休憩させてもらえませんか？ 少し休憩させてもらえないでしょうか？ 少し休憩を取らせていただけませんか？ 少し休ませてもらえませんか？ 少し休んでもよろしいでしょうか？ 少し休んでいいですか？ 少し休ませてください。 少し休ませて。 Probably we get the idea if you say like I mentioned.

こんにちは。あまり自信はありませんが、 「ちょっと休憩〜。」「少し休ませて。」 などは、どうでしょうか？(´･_･`)