Can you clarify a little bit please.
What Release and Version?
Do you want to import only one work order parts list at the time? Or you need to import many?
Depending of your version, you can import parts by Copy/Paste or Import into a Work order parts.
Otherwise, there is no inbound available for WO Parts list, but only for Item Bill of material. If somebody know about a WO parts list inbound, please tell me!!!