my $xml = "<tbody>one\ttwo\tthree</tbody>\n"x40;

$xml =~ s#<tbody>((?:[^<]+|<(?!/?tbody>))+</tbody>(?:\s*<tbody>(?:[^<]+|<(?!/?tbody>))+</tbody>)*)#"<tbody>\n".${TableBody(\$1)}."\n</tbody>"#gies;
print $xml;

sub TableBody
{
    my ($line) = @_;
    $temp = "$$line";
    $temp =~s#</tbody>$##;
    $temp =~s#\t#</para></entry><entry><para>#g;
    $temp ="<row><entry><para>$temp</para></entry></row>";

    $temp =~s#<tbody>#<row><entry><para>#g;
    $temp =~s#</tbody>#</para></entry></row>#g;
    return \$temp;
}