That's because, you are not passing any data to your delete method that could enable it to redirect to the appropriate page. Following sample gives you an idea...
Delete method
public ActionResult Delete(int itemId, int pageNo)
{
return RedirectToAction("Index", "Home", new { pageNumber = pageNo });
}
While rendering the delete link also include the page number in the link generated, i.e., your view model should also contain the current page number. So instead of:
http://someurl/home/delete?itemId=1
generate:
http://someurl/home/delete?itemId=1&pageNo=5