Hello,

You can use html and style inline and css...

So if you want a table like in your example...

You can write a table in xml view...

EG:

<group>
  <table style='width:100%;' border='1'>
    <tr>
      <th style='width:40%; font-weight:bold'><label for="name"/></th>
      <th style='width:20%; font-weight:bold'><label for="is_company"/></th>
      <th style='width:40%; font-weight:bold'><label for="category_id"/></th>
    </tr>
    <tr>
      <td><field name="name" default_focus="1" placeholder="Name"/></td>
      <td><field name="parent_id"/></td>
      <td><field name="category_id" widget="many2many_tags" placeholder="Tags..."/></td>
    </tr> 
 </table>
</group>