use DrupalCoreLink;

$row[] = [
  'data' => Link::createFromRoute(...),
  'class' => 'middle',
];
$row[] = [
  'data' => Link::createFromRoute(...),
  'class' => 'middle',
];
$rows[] = ['data' => $row, 'no_striping' => TRUE];

return [
  '#theme' => 'table',
  '#header' => [..],
  '#rows' => $rows,
];