What is allowed:

The host machine and external screens that are shared with the Proctoring tool session, printed books and notes, paper, and pen are the items allowed.

What is not allowed:

Please note that you are not allowed to use other machine aside from your host, and there should be no other electronic devices other than your exam machine within your exam area.

You may also visit Am I allowed to use another devices for other purposes during the exam? for more information.