The current style is awkward, with the link below & inside the table. To make it more consistent with other modules, change the menu item type flag to Local Action for $items['admin/structure/custom_pagers/add'] :

custom_pagers.module
Line 25: 'type' => MENU_CALLBACK,
replace with:
Line 25: 'type' => MENU_LOCAL_ACTION,

The following is then no longer needed:
custom_pagers.admin.inc

Line 33:     $rows[] = array(array(
Line 34:       'data' => l(t('Add a new custom pager'), 'admin/structure/custom_pagers/add'),
Line 35:       'colspan' => 2,
Line 36:     ));

On a related note, the table header for 'Operations' is blank:
Line 15: $header = array(t('Title'), t('Node list'), t('Visibility'), '');
replace with:
Line 15: $header = array(t('Title'), t('Node list'), t('Visibility'), t('Operations'));