<?php
$vid = db_result(db_query("SELECT vid FROM {vocabulary} WHERE name = '%s'", t('Topic')));
$vocabulary = taxonomy_get_vocabulary($vid);

$terms = array(
  array(
    'name' => t('Cats'),
    'vid' => $vid,
  ),
  array(
    'name' => t('Dogs'),
    'vid' => $vid,
  ),
  array(
    'name' => t('Bunnies'),
    'vid' => $vid,
  ),
);

foreach ($terms as $term) {
  drupal_execute('taxonomy_form_term', $vocabulary, $term);
}
?>