use HTML::TableExtract;
use WWW::Mechanize;

my $user_agent='Mozilla/5.0 (Windows; U; Windows NT 6.1; nl; rv:1.9.2.13)Gecko/20101203 Firefox/3.6.13';

my $mech = WWW::Mechanize->new(autocheck => 0, agent = $user_agent );
if ( $mech->success ) {
    my $html_string = $mech->content;
    my $headers = ['col1', 'col2', 'col3', 'col4', 'col5'];
    my $te = HTML::TableExtract->new( headers => $headers );
    my @tables = $te->parse($html_string)->tables;
}
...