There isn’t large number of parameters.
On the left side of the interface is Tree View with the Material Categories.
The header of a Categories Tree View contains two buttons: Expand All Branches and Collapse All Branches.
For the selected Category materials are displayed on the right side in Thumbnail Viewer. On top of the Thumbnail Viewer is a Slider for change the size of Icons.
Nearby is a Medium Preview window. Right click (RM) opens/close a full preview image (1000x1000px).
Two checkboxes for a choice of the destination of an applied Material: To selected (active) 3ds Max Material Editor slot or selected object node/objects group. With the button Assign Material selected Material will be applied to the target. Below the button – name of the selected Material.
Shift+M = Assign Material to Material Editor Active slot
Shift+O = Assign Material to selected Object(s)
Max Subdivs – when enabled, controls the maximum number of reflection/refraction subdivs. Affect to material when importing to the Material Editor or the selected object.
Real-World Scale – enables Real-World Map Size in bitmap texture of material. The texture map appears in the material with correct scaling depending on your scene units (the system and display units shall be the same).