a posição pegajosa

<!--In your stylesheets just add this one line:-->
<style>
thead th { position: sticky; top: 0; }
</style>

<table>
    <thead>
        <tr>
            <th>column 1</th>
            <th>column 2</th>
            <th>column 3</th>
            <th>column 4</th>            
        </tr>    
    </thead>
    <tbody>
      // your body code
    </tbody>
</table>
Sandy4467