1   4
2   5
3

<td>
  {section name=myitem loop=$items max=(($itemcount/2)+0.499)}
    {$items[myitem]}
  {/section}
</td>
<td>
  {section name=myitem loop=$items start=(($itemcount/2)+0.499)}
    {$items[myitem]}
  {/section}
</td>