A/B Tests for Kindle Ebook?

I'm not good at deciding. Especially not with titles and covers. Do you think it's possible to sell two or three times the same book, everytime with a different title and cover? KDP select ofc.

Idea behind this is to see which sells more and delete the other 2.

Nope. Amazon will block it based on duplicate content. You can however track sales and tweak KWs, Cover, title etc in case you don't see sales.