Another issue with Tables

I have a new issue with tables where I am not able to add custom css to individual cells or columns I just get the message "No custom styles" you can see the video at
youtu-DOT-be/2mSKsuB2p5k
I tried with clear cache in Firefox and Chrome

I also have another issue. I have a page that I load into an article. It has rows on the page but when I import the rows of the table I am not able to delete.
youtu-DOT-be/BpyflzCA8_0

Hi
1/ custom styles : you must first create them in the "custom styles" tab

2/ I will check the import issue
CEd