Try this
<container id="main">
<attachment_group class="vertical_arrange" vertical_alignment="top,extend" />
<widget class="text" id="cdsc" auto_size="vertical" colour="faded text" size="small" />
<!-- Ability list table -->
<widget class="table" id="calL" mode="fill_rows,stripe_rows,select_rows" layout="24,-5,-3,-3">
<list id="column_widget_properties">
<record indx="0" alignment="left,centre_y" colour="faded text" />
<record indx="1" alignment="left,centre_y" />
<record indx="2" alignment="left,centre_y" />
<record indx="3" alignment="left,centre_y"/>
</list>
<list id="column_table_properties">
<record indx="0" sort_disabled="true" left="5" />
<record indx="1" sort_disabled="true" >
<record id="column_heading">
<flags id="alignment" value="left,centre_y" />
<translation id="text" translation_id="227966" type="use" value="Player" />
</record>
</record>
<record indx="2" sort_disabled="true" >
<record id="column_heading">
<flags id="alignment" value="left,centre_y" />
<translation id="text" translation_id="314426" type="use" value="Ability[COMMENT: player popup info panel - scout current ability rating]" />
<translation id="hint" translation_id="310135" type="use" value="Current Ability[COMMENT: contract offer screen - comments table]" />
</record>
</record>
<record indx="3" sort_disabled="true" >
<record id="column_heading">
<flags id="alignment" value="left,centre_y" />
<translation id="text" translation_id="314427" type="use" value="Potential[COMMENT: player popup info panel - scout potential ability rating]"/>
<translation id="hint" translation_id="310136" type="use" value="Potential Ability[COMMENT: contract offer screen - comments table]" />
</record>
</record>
</list>
</widget>
</container>
Edit: the container might not be needed in your setup.