for($i=0;$i<$num;$i++)
{
echo "<input type=\"text\" name=\"item_".$i."_a\">\n";
echo "<input type=\"text\" name=\"item_".$i."_b\">\n";
echo "<input type=\"text\" name=\"item_".$i."_c\">\n";
}
Would give you your 3 items per number - print_r($_REQUEST) would give all coming through. Then place into your DB as required...