Theme a series of form elements into a table (Drupal 6)

theme_D6MODULE_table_form.php

<?php

/**
 * Theme a series of form elements into a table (Drupal 6).
 */
function theme_D6MODULE_table_form($form) {
  $header = array();
  $rows = array();

  foreach (element_children($form) as $i) {
    $row = array();
    if (!isset($form[$i]['#sorted'])) {
      uasort($form[$i], 'element_sort');
    }
    foreach (element_children($form[$i]) as $f) {
      $this_element = &$form[$i][$f];
      if (isset($this_element['#title'])) {
        if (!isset($header[$f])) {
          $header[$f] = $this_element['#title'];
        }
        unset($this_element['#title']);
        if (isset($this_element['#label'])) {
          $this_element['#title'] = $this_element['#label'];
        }
        $row[] = drupal_render($this_element);
      }
    }
    $rows[] = array(
      'data' => $row,
    );
  }

  return theme('table', $header, $rows);
}

/**
 * Implements hook_theme().
 */
function D6MODULE_theme() {
  return array(
    'D6MODULE_table_form' => array(
      'arguments' => array('form' => NULL),
      'file' => 'D6MODULE.admin.inc',
    ),
  );
}