unificare due div in uno

[Progeny]

CSS:

div.tab_box {
  padding-bottom: 5px;
  border-bottom: 1px solid #BCD2E6;
}

div.tab_box h4 {
  background: url(../images/css/tab/tab2.png) no-repeat;
  border-bottom: 1px solid #BCD2E6;
  font-size: 100%;
  line-height: 30px;
  text-indent: 10px;
}

div.tab_box h4:hover {
  color: #FF9C00;
  background: url(../images/css/tab/tab1.png) no-repeat;
} 

HTML:

<div class="tab_box"><h4>Attivita`</h4>
  <div>
    <table style="width: auto;" cellpadding="1" cellspacing="1">
      <tr>
        <td>[img]images/profile/reg_date.png[/img]</td>
        <td>Iscritto dal</td>
        <td><?php echo($profile['registration_date']); ?></td>
      </tr>
      <tr>
        <td>[img]images/profile/time.png[/img]</td>
        <td>Ultima visita</td>
        <td><?php echo($seen); ?></td>
      </tr>
      <tr>
        <td>[img]images/profile/chart.png[/img]</td>
        <td>Voti ricevuti</td>
        <td><?php echo(Profile_CountVotes($uid, $mysql)); ?></td>
      </tr>
    </table>
  </div>
</div>

va meglio così?
ps.: cell padding e cell spacing per una tabella, in CSS come si scrive?