Which table or field which store the remarks from approval activity after successful submission.Do you have any table in Adobe campaign
The response from the approval activity are stored in the Answers(responses) nested table in the xtk:workflowTask schema.
It can also be accessed from xtk:workflow schema directly as it is linked with xtk:workflowTask . Refer to the screenshot below on how to add the column and check the responses from approval activity.
Hope this helps