<html> <body> <table cellpadding="0" cellspacing="0"> <tr> <td> <table style="table-layout: fixed;" cellpadding="0" cellspacing="0"> <tr> <td style="background: lightgreen;">a</td> </tr> </table> </td> <td> <table style="table-layout: fixed;" cellpadding="0" cellspacing="0"> <tr> <td style="background: lightblue;">b</td> </tr> </table> </td> </tr> </table> </body> </html>