People use task-managment in two very different ways: first very similar to project-management, second for questions related to OS-level task management.
I think the first case should be forbidden (with a comment in tag description), only project-management used for such questions.
BTW there is a typo in tag name
Good point! I just created that tag-wiki accordingly (and re-tagged the two non-matching questions). One more thought here is that in the future we might need a third variant of "task manager": todo lists. As for now, they should fit into project-management (project: "My Tasks" :D).
I second Izzy's recommendation for project-management for one of the meanings.
On top of that, use process-management for tasks-in-OS-sense. This has a benefit of both not using the (now-can-be-banned) confusing dual meaning tag; AND being more technically accurate, since they are called Processes on virtually every OS, even Windows ("Process Explorer" is what people with a clue use instead of "Task Manager")
