I think Inside the view manager have a option.
That will let you copy a view. I don't see a way to copy a tab on a view from there...
I haven't seen a way of doing it either. I usually just duplicate all the resources in the original tab, then I move all those duplicates to the new tab.
This would be a good feature idea.
Here's a similar idea
Good idea superfly, I didn't think about moving the resources to another tab. That'll have to do for now, and should help speed up things somewhat. Thanks!