There is no option to export from RQM to Excel in 301x but yes in RQM 4.0 you can export artifacts in csv format.
No there is no utility to import from PDF to RQM. Also note that the exported csv data is for print purpose, it should not be considered for import again.

However you can use RQM's REST API to export data in xml format. This data can be imported back into RQM on same server or other server.

Essentially you don't need to export artifact from RQM except for the print/reporting purpose. IMO It is good practice to maintain artifacts in central repository on RQM so team can easily collaborate but print it for offline purpose. Let me know if you have any specific scenario where exporting out from RQM would be useful.