If you can connect to the desktop computer directly from your laptop, yes,
it should be possible provided you have Entourage X on both machines. On
the Desktop, quit all Office applications except Entourage, and then go to
Entourage -> Turn Off Office Notifications. Then quit Entourage.
On the laptop computer, connect to the Desktop, and follow this path:
Desktop HD/Users/<Your User>/Documents/Microsoft User Data/Office X
Identities/<Your Identity>/
You can either (a) drag the "<Your Identity>" folder over to the exact same
location on the laptop computer to make a copy, or (b) Command-Option-drag
the "<Your Identity>" folder over to the exact same location on the laptop
computer to make an alias.
The first option (a) will make a copy so that you can make changes on the
laptop and then drag the folder back to the desktop computer when you're
done. The second option (b) accesses the desktop's copy of the database
directly so that you don't need to copy the identity folder back over to the
desktop computer. However, it will only work if you are connected to the
desktop via the network.
When you first open Entourage after copying, your data might not appear. If
that is the case, you need to go to Entourage -> Switch Identity, and
manually select your identity.