Firstly a big thank you for the example code. It's saved me hours of coding pagination, formatting etc. and keeps the tables looking consistent with WP admin
I'm not sure if it's necessary, but I added a
call around the delete URL where actions are setup in the column_name() function. Then I added a check in my delete code to
to verify the nonce.
I also noticed the bulk delete automatically added a nonce argument to the URL so also added a check delete bulk deletion,
check_admin_referer('bulk-' . $this->_args['plurals');
Hopefully this is the correct thing to do. Can you confirm ?