The operators on this panel are explained from left to right.
A dropdown list of all the material slots on the active object with a material. If the material slot is empty it will be ignored.
This is the display name of the active material. After updating this you will be prompted to update the material.
This creates a new material that is compatible with the addon. You will not be able to view this material unless explicitly set to faces in edit mode or all other material slots on the object are deleted.
This moves the active materital slot one place up, it does not affect how the materials on the object are viewed however.
This moves the active materital slot one place down, it does not affect how the materials on the object are viewed however.
This deletes the active material from the .blend file and all the relevant data associated with it. There will be a prompt before deleting, however if you hold down SHIFT while clicking on the operator, the prompt will be overridden.
This will update the material if there are any significant changes made by the you.