chromium/third_party/blink/web_tests/tables/mozilla/core/col_widths_auto_autoPer.html

auto table 
<table border>
 <tr>
  <td width=0%>0% 0% 0% 0%</td>
  <td>auto</td></td></tr>
</table>
<BR>
auto table - % width cell increases table width based on % cell
<table cellspacing=10 cellpadding=10 border>
 <tr>
  <td width=10%>10% 10%</td>
  <td>auto</td></tr>
</table>
auto table - % width cell increases table width based on % cell
<table cellspacing=10 border>
 <tr>
  <td width=10%>10%</td>
  <td>auto</td></tr>
</table>
<BR>
auto table - % width cell increases table width based on % cell which makes it largest
<table cellspacing=10 border>
 <tr>
  <td width=10%>10%</td>
  <td width=1%>1%</td>
  <td>auto</td></tr>
</table>
<BR>