class ComponentTableItem extends JTable
{
  function __construct(&$db)
  {
    parent::__construct('#__cmp_item', 'id', $db);
    JTableObserverTags::createObserver($this, array('typeAlias' => 'com_component.item'));
 }
}

public function delete(&$pks)
{
    $db = JFactory::getDbo();

    $pks = (array)$pks;

    // Iterate the items to delete each one.
    foreach ($pks as $i => $pk) {
        $item = JTable::getInstance('item', 'ComponentTable');
        $item->load($pk);
        //...do some stuff
        //and finally delete the item
        $item->delete($pk);
     }
 }