Fix for this issue is now available in the latest update of InDesign 2020.
In the Creative Cloud Desktop application, click on the Updates section on the left. You should be able to see the Update available for InDesign. Please update your InDesign application to this version to try out the fix.
Let us know in the comments section if you face any problem with the updation process.
Adobe InDesign TeamDoug Bailey commented
This is a huge pain. Please fix this so that the Ctrl-Left and Ctrl-Right behaviour is consistent throughout the application. (Note that Ctrl-Shift-Left and Ctrl-Shift-Right, for selection, work as usual when the cursor is in a table.)