Tor website says "tor browser bundle" is enough if only browsing is required. Is it also equally safe to use for downloading purpose ?
Anything you do from a web browser is (technically) web browsing. So, downloading counts as web browsing. What the Tor website (probably) means in this case is that if you want to do something which your browser is incapable of doing — such as a remote desktop session, through e.g. rdb, vnc or ssh protocols, you'll have to set up Tor to work more generally, so that programs implementing these protocols can use it.
However, if you go for the Tor browser option, your actions in other programs will not be protected. Notably, if you use an alternate browser, it will not be protected.