How to create a new table in drupal without uninstall/installing the custom module
The proper way to do this is to simply implement hook_update_N() and manually add the table that you've added to hook_schema():

/**
 * Add the foo table.
 */ 
function MYMODULE_update_7100() {
  $table_name = 'table_name';
  $schema = drupal_get_schema_unprocessed('MYMODULE', $table_name);
  db_create_table($table_name, $schema);

  return $table_name . ' table created.';
}


That goes in your module's .install file along with the schema hook, and you'll need to run drush updb (or run through the UI at /update.php) for the changes to take effect.