I usually use viewDidAppear method to do some UI stuff on the view after it finished appearing and I used this method in various situations were it was very useful,
The UITableViewDelegate has these functions:
func tableView(_ tableView: UITableView, willDisplay cell: UITableViewCell, forRowAt indexPath: IndexPath)
func tableView(_ tableView: UITableView, didEndDisplaying cell: UITableViewCell, forRowAt indexPath: IndexPath)
The cell itself does not have callbacks for this.