$Txt =~ s!(<table.*?>)(.*|\n)?(</table>)!
               my $TD = $2; my $first = $1; my $last = $3;
               unless ($TD =~ /id="CODE"/) {
                  $TD =~ s#<br>#\n#isg;
               } "$first$TD$last"!eisg;

##</code><code>##

<table>
<tr><td>First Table</td</tr>
</table>
<table>
<tr><td>Second Table</td</tr>
</table>
<table>
<tr><td>Third Table</td</tr>
</table>