@Data=<DATA>;
foreach $line(@Data)
{
	if ($line=~s#(<h([0-9]+)>(?:.+?))#$1#)
	{
		$curr=$2;
		$endtag='</table>';
		$line=~s#^(<h[0-9]+>)?(.+?$)#$1<tr><td>$2</td></tr>#;

		if ($prev=~m#^$#)
		{
			$line=~s#<h[0-9]+>#<table>#g;
		}
		elsif ($prev == $curr)
		{		
			$line=~s#<h[0-9]+>##;
		}
		elsif ($prev > $curr)
		{
			$x=$prev-$curr;
			for ($i=0; $i<$x; $i++)
			{
				$line="$endtag\n".$line;
			}
			$line=~s#<h[0-9]+>##;
		}
		$line=~s#<h[0-9]+>#<table>#g;
	}

	$prev=$curr;

	$Final.=$line;
}

$Final=$Final.'</table>';

print $Final;


__DATA__
<h1>Heading Level 1
<h2>Heading Level 2
<h2>Heading Level 2
<h2>Heading Level 2
<h3>Heading Level 3
<h3>Heading Level 3
<h2>Heading Level 2
<h1>Heading Level 1

##</code><code>##

<table><tr><td>Heading Level 1</td></tr>
<table><tr><td>Heading Level 2</td></tr>
<tr><td>Heading Level 2</td></tr>
<tr><td>Heading Level 2</td></tr>
<table><tr><td>Heading Level 3</td></tr>
<tr><td>Heading Level 3</td></tr>
</table>
<tr><td>Heading Level 2</td></tr>
</table>
<tr><td>Heading Level 1</td></tr>
</table>