Hi Fabio,
Thanks for reaching out with your BoldGrid Post and Page Builder for WordPress questions.
I think you may be experiencing issues with functionality overall because Post and Page Builder was created to be compatible with themes created on the BoldGrid Theme Framework.
The Post and Page Builder allows you to switch between the different editors available on your website, and you should be able to find the table controls described in that article by switching to the WordPress editor.
Alternatively, if you do not want to switch to the WordPress editor for that particular page and want to continue using the Post and Page Builder, then you could try using the TablePress plugin to manage the table content for your pages.
Hopefully one of those solutions helps you create the design you are looking for and please let us know if you have any other questions!