<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>Multiple counter</title>
  </head>
  <body>
    <div id='counter_app'></div>
    <script id='counter_template' type='text/ractive'>
      <h1>Multiple counter</h1>
      <input type='text' value='{{new_title}}' />
      <button on-click='addItem(new_title)'>Add</button>
      <table>
        {{#each items:i}}
        <tr>
          <th><button on-click='countUp(i)'>+</button></th>
          <th>{{title}}</th>
          <th>{{count}}</th>
        </tr>
        {{/each}}
      </table>
    </script>
    <script src='http://cdn.ractivejs.org/latest/ractive.min.js'></script>
    <script src='counter.js'></script>
  </body>
</html>

<!DOCTYPE html>
<html>
  <head>
    <meta charset="UTF-8">
    <title>Multiple counter</title>
  </head>
  <body>
    <div id='counter_app'></div>
    <script id='counter_template' type='text/ractive'>
      <h1>Multiple counter</h1>
      <input type='text' value='{{new_title}}' />
      <button on-click='addItem(new_title)'>Add</button>
      <table>
        {{#each items:i}}
        <tr>
          <td><button on-click='countUp(i)'>+</button></td>
          <td>{{title}}</td>
          <td>{{count}}</td>
        </tr>
        {{/each}}
      </table>
    </script>
    <script src='http://cdn.ractivejs.org/latest/ractive.min.js'></script>
    <script src='counter.js'></script>
  </body>
</html>

Use td instead of th
Use td instead of th
