<!DOCTYPE html>
<html>
<head>
  <style>
  div { -moz-column-width:200px; -moz-column-count:2; -moz-column-gap:0; border:2px solid black; height:200px; }
  div.gap { -moz-column-gap:80px; }
  span { display:inline-block; width:100px; }
  </style>
</head>
<body>
  <table width="1"><tr><td><div>
    <span></span>
  </div></tr></td></table>
  <table width="1"><tr><td><div class="gap">
    <span></span>
  </div></tr></td></table>
</body>
</html>