If you have the virtualbox additions installed (which it should be IIRC in the sage virtualbox image), then you can copy some text in your host machine and paste it in the guest sage command line by pressing shift and insert at the same time.
If you have the virtualbox additions installed (which it should be IIRC in the sage virtualbox image), then you can copy some text in your host machine and paste it in the guest sage command line by pressing shift and insert at the same time.