I'd like to a add a piece of example code to what Cody Pendant said:

my $table_tmpl = new HTML::Template filename => 'table.tmpl';
my $result     = new HTML::Template filename => 'comparison_page.tmpl'
+;

my ($first, $second);
$table_tmpl->param(data => get_table_data(key => 'first'));
$first = $table_tmpl->output;
$table_tmpl->param(data => get_table_data(key => 'second'));
$second = $table_tmpl->output;

$result->param(first => $first, second => $second);

print $result->output;
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That's a common pattern -- to generate several pieces of HTML using one template and different data and then insert these pieces into final output template.