PMA\libraries\Table::isMerge PHP Method

    public function isMerge()
    {
        return $this->isEngine(array('MERGE', 'MRG_MYISAM'));
    }

/**
 * Prints Html For Export Options
 *
 * @param String         $export_type    Selected Export Type
 * @param String         $db             Selected DB
 * @param String         $table          Selected Table
 * @param String         $multi_values   Export selection
 * @param String         $num_tables     number of tables
 * @param ExportPlugin[] $export_list    Export List
 * @param String         $unlim_num_rows Number of Rows
 *
 * @return string
 */
function PMA_getHtmlForExportOptions($export_type, $db, $table, $multi_values, $num_tables, $export_list, $unlim_num_rows)
{
    global $cfg;
    $html = PMA_getHtmlForExportOptionsMethod();
    $html .= PMA_getHtmlForExportOptionsFormatDropdown($export_list);
    $html .= PMA_getHtmlForExportOptionsSelection($export_type, $multi_values);
    $_table = new Table($table, $db);
    if (strlen($table) > 0 && empty($num_tables) && !$_table->isMerge()) {
        $html .= PMA_getHtmlForExportOptionsRows($db, $table, $unlim_num_rows);
    }
    if (isset($cfg['SaveDir']) && !empty($cfg['SaveDir'])) {
        $html .= PMA_getHtmlForExportOptionsQuickExport();
    }
    $html .= PMA_getHtmlForAliasModalDialog($db, $table);
    $html .= PMA_getHtmlForExportOptionsOutput($export_type);
    $html .= PMA_getHtmlForExportOptionsFormat($export_list);
    return $html;
}