You can organize materials into custom folders for easy reference and management. By doing this, you are, effectively, customizing a user archive. For more information, see Use the Presenter Archives.
On the Materials tab, the right pane, or material palette, is where you edit and manage your materials for your scene. Materials are taken from the archives into the palette where they are edited. You can then save the palette into a Autodesk Navisworks palette file (NWP) for use in other scenes too.