Stream Music from PC to Laptop in your LAN
Just open MediaMonkey, go to File menu, click on "Add/Rescan Track to the Library" and locate the network share (you created in your desktop PC) containing your music collection folder.
MediaMonkey will take some time to scan your collection, but you don't need to do this everytime you open MediaMonkey in you notebook, just do it when you know (or think) there are new tracks in your collection that this MediaMonkey installation needs to know about.
Some pages in the Net give instructions on how to share a single MediaMonkey database file between computers but I don't recommend this. You will still have to use the Rescan menu option to update (even if faster) the database to include alternative paths for every entry but using the network share prefix instead of the local drive prefix (used by the native MediaMonkey, the one installed in the computer holding your music collection) and so, when you search for song A, you will get two matches (the one with the network share prefix will work from your laptop). A mess.