I experimented with this:

#!/usr/bin/perl

use strict;
use warnings;
use HTML::TreeBuilder::XPath;
use LWP::Simple;
use Test::WWW::Mechanize;
use WWW::Mechanize::TreeBuilder;
use Data::Dumper::Concise;

my $tree = HTML::TreeBuilder::XPath->new;
my $mech = Test::WWW::Mechanize->new;
WWW::Mechanize::TreeBuilder->meta->apply($mech);
$tree->parse_content(get 'http://www.educa.ch/dyn/79376.asp?id=1187');
print Dumper($tree->as_text('//tr'));
[download]

Update:: not finished - will integrate $mech->find_xpath later.