Apple numbers - Keyboard Shortcut - Start editing the table that is selected

I have a sheet with two tables. I am trying to automate moving some numbers from one table to the other. I would like to find a keyboard shortcut that lets me move back and forth between the tables without using the mouse.

When on ‘table 1’ I can press ‘escape’ then ‘tab’ and cycle through which table is selected, but I don’t know how to start editing the table that is selected (without using the mouse).

I found this on apples support page

Select the first cell in a selected table - Option-Return

But this only results in an alert sound like that action is not allowed. No cell is selected, just the entire table on that sheet.

MBP 2015 - Catalina 10.15.4
Apple Numbers 6.2.1
Keyboard Maestro 9.0.3 (I don’t have any triggers that would interfere with Option-Return. The behavior is the same if I have Keyboard Maestro closed)