Переменные для таблицы. Thead, rows

basf_views.module

/**
 * Implements hook_preprocess_views_view_table().
 */
function basf_views_preprocess_views_view_table(&$variables): void {
    /** @var \Drupal\views\ViewExecutable $view */
    $view = $variables['view'];
    $trows = [];
    $thead = [];

    if ($view->id() === 'listing_' . $view->current_display) {
        switch ($view->current_display) {
            case 'msds':
            case 'tds':
                foreach ($variables["header"] as $column) {
                    $thead[] = $column["content"];
                }
                $variables['thead'] = $thead;

                foreach ($variables['rows'] as $index => $row) {
                    foreach ($row['columns'] as $column) {
                        $trows[$index][] = $column['content'][0]['field_output'];
                    }
                }
                $variables['trows'] = $trows;
            break;
        }
    }
}