You can use the $order_total_amount to check the order total to see if you should add the extra charge to:
Code:
$this->quotes = array('id' => $this->code,
'module' => MODULE_SHIPPING_TABLE_TEXT_TITLE . $show_box_weight,
'methods' => array(array('id' => $this->code,
'title' => MODULE_SHIPPING_TABLE_TEXT_WAY,
'cost' => $shipping + MODULE_SHIPPING_TABLE_HANDLING)));
Something like:
Code:
$this->quotes = array('id' => $this->code,
'module' => MODULE_SHIPPING_TABLE_TEXT_TITLE . $show_box_weight,
'methods' => array(array('id' => $this->code,
'title' => MODULE_SHIPPING_TABLE_TEXT_WAY,
'cost' => $shipping + MODULE_SHIPPING_TABLE_HANDLING + ($order_total_amount > 10 ? .80 : 0))));
Now if you need .80 per Item over 10.00 then you would need to do a little more customization here ...