I’m not sure if I’m following you but I think I’m having the same predicament. In my case I must give some space to the ADBannerView at the top of the screen so what I did was in the viewDidLoad method I added:
[self.tableView setContentInset:UIEdgeInsetsMake(50,0,0,0)];
the values it takes are UIEdgeInsetsMake(top,left,bottom,right).
Alternatively the same with Swift:
self.tableView.contentInset = UIEdgeInsetsMake(50, 0, 0, 0)
Swift 4.2:
self.tableView.contentInset = UIEdgeInsets(top: 50, left: 0, bottom: 0, right: 0)