WP_Editor – Setting render location on page

I’m trying to include wp_editor in a settings page.

public function addEditor($content = '')
{       
    $editor_id = 'createposteditor';

    $args = array(
        'textarea_rows' => 15,
        'teeny' => true,
        'quicktags' => false,
        'editor_class' => 'createpost-editor'
    );

    return wp_editor( $content, $editor_id, $args  );
}   

and then I echo it out on the settings page:

<tr>                    
    <td align="left" scope="row">                                                                 

        <h1>Add content (optional)</h1>
        '. $poster->addEditor() .'                                           
    </td>
</tr>

My issue is, the editor always gets rendered at the top of the page, not from within the <td> as I require.