Why doesn't safari delete undownloaded files?

Question

safari

I finally switched to Safari (the latest version of course) with all the tabs from Chrome (the latter often lags lately, it seems to eat more resources, and in general in Mac OS and not with native programs .. okay .. BUT I won’t leave MS Office looks like never :D). Okay, away from the lyrics. Sobsno subject. Where to set up? And is it possible? And that irritates zhuut.