The wiki module sometimes sets the currently active tab as a link.
This is because the tab itself has modal states, and the link allows you to return to the initial state. Mostly this seems to duplicate buttons already present within the tab content (usually "cancel" or "no" buttons).
The only exception is there appears no way to return to the list of page versions within the history tab once you click on a specific revision without clicking on the link in the tab.
If a suitable link was added within the tab, this feature could be removed from the wiki module and then support for having the current tab linked could be removed from the renderer for displaying tabs.