these pages shows the accessibility standards for tables.
https://www.w3.org/WAI/tutorials/tables/
https://www.w3.org/WAI/tutorials/tables/two-headers/
https://www.w3.org/WAI/tutorials/tables/irregular/

For these two sub links "Tables with two headers" & "Tables with irregular headers", they are looking for "scope=col", "scope=row", "scope=colgroup", "scope=rowgroup".

There doesn't seem to be any built in support for "scope" to be added when using the table wizard, having set on the Accessibility tab a Heading for both a Row & Column.

Add support for "scope" be added to tables created in the Rich Text Editor.

(https://www.telerik.com/forums/table-wizard---scope-attribute-for-tables#XKGf9DNED0a8Cdxvzh7Qvg)