Hello again Adriano.

This is not possible with the plugin's built-in features, due to the limitations of the 3rd party HTML5 library we're using for the export tools. However, I will tell you which file in our plugin you need to change to get the PDF files to export in landscape. It will be applied to all tables, though, and you won't be able to choose between two orientations from within the plugin.

Please open ../wp-content/plugins/wpdatatables/source/class.wpdatatable.php, and around line 3310, you'll find this:

if (!empty($this->_tableToolsConfig['pdf'])) {
   $exportButtons[] =
      array(
         'extend' => 'pdfHtml5',
         'exportOptions' => array('columns' => ':visible'),
         'orientation' => 'portrait',
         'title' => $wdtExportFileName,
         'text' => __('PDF', 'wpdatatables')
      );
}

Also, around line 3394 you'll find another instance of 'portrait'. Simply change those two to 'landscape' and it will change the output format.

Best regards.