Not sure why you would want to do that, as this is how GMail represents your default folders and labels, when connecting through IMAP.
The beauty of this is, that moving mails between the IMAP folders in Outlook, marking mails as read etc., will also be reflected when using webmail, smartphones and other IMAP clients.
If you do not want this, I think your only option is to configure Outlook to use POP3, rather than IMAP, to get your GMail.
As far as I remember, you can't change an IMAP account to a POP3 account in Outlook. You'll have to create a new account, manually specifying server settings.