How do I remove PCs from the Tabs dropdown in IE11?

Windows 8.1 has a neat feature where you can pull up a list of open browser tabs from your other devices. I like this feature, but the list of devices is already starting to become littered with PCs I either no longer own or never owned but signed into once to try them out.

Is there any way to cleanse this list of unwanted devices? Or at least rename them? I have two SURFACEs and two YOGAs in my list.