[gentoo-user] OT: Firefox - saved or not ot be saved...

Hi,

there is one feature of forefox, which bugs me:
On the same site (www.blenderswap.com) I click
to files to download. One is a *.blend, the
other one is a *.rar.
When I click the *.blend, the file gets downloaded
and stored on my hd at once -> bad!
When I click the *.rar, the file gets NOT downloaded
at once and instead I am offered a dialog, which
asks what to do.

I looked into Preferences->Application, which lists
filetypes and the according action and DONT find
an entry for *.blend files.

Where can I change the action selected by Firefox
which gets executed for a certain filetype else?

Thank you very much in advance for any help!
Best regards,
mcc