Currently, you can only add one magnet link at a time. It would be awesome to have a bulk import functionality where you can paste a list of magnet links and they're parsed as multiple torrents.
If you're interested in this feature, I'd be happy to give it a go.
One idea could be to make the input in the current UI a text area that allows multiple links.
Another idea is to listen to a global "paste" shortcut and process the clipboard for magnet links