<table role="presentation" width="100%" cellspacing="0" cellpadding="0" border="0">
  <tr>
    <td align="center">

      <table role="presentation" width="600" cellspacing="0" cellpadding="0" border="0" style="width: 100%; max-width: 600px;">
        <tr>

          <td width="50%" valign="top" style="padding: 20px; background-color: #f8f9fa;">
            <h3 style="margin: 0 0 10px 0; font-family: Arial, sans-serif;">Left Column</h3>
            <p style="margin: 0; font-family: Arial, sans-serif; line-height: 1.5;">
              This is the text for the left side. It will stay side-by-side with the right column.
            </p>
          </td>

          <td width="50%" valign="top" style="padding: 20px; background-color: #e9ecef;">
            <h3 style="margin: 0 0 10px 0; font-family: Arial, sans-serif;">Right Column</h3>
            <p style="margin: 0; font-family: Arial, sans-serif; line-height: 1.5;">
              This is the text for the right side. Note the different background colors to visualize the split.
            </p>
          </td>

        </tr>
      </table>

    </td>
  </tr>
</table>