The left-middle panel shows the model's materials slots (left column) and the respective mappings (right columns).
The names you see in the left column are the names of the materials that were set in the .obj file. In My AR Studio these becomes slots to which a material from the library can be assigned.
The right column shows the name of the library material which is assigned to the relative slot.
You can assign a library material to a model's material slot by clicking and dragging a material card from the library to the row of the slot.