<table>
    <tr>
        <th>Key</th>
        <th>Copies</th>
        <th>Workers</th>
    </tr>

    {% for title, keys in who_has.items() %}
    <tr>
        <td>{{ title }}</td>
        <td>{{ keys | length }}</td>
        <td>{{ keys | join(", ") }}</td>
    </tr>
    {% endfor %}
</table>