We are not familiar with a way to enable the smart tag menu at run-time. Actually, we are not sure this is possible. In my opinion the best decision here is to create your own contextual menu with the same facilities. What you should do is to subscribe to the mouse down event of RadTabStrip
and check whether the right mouse button was hit to show the context menu.
If I could be of further assistance, please feel free to write me back.
All the best,
the Telerik team