avia advanced editor: how to set tables to be horizontally centered

Hello,

can’t find out a way to horizontally center the table element via avia. I am using a “full width” page, and if I embed a single-column row not 100% wide (let’s say 80%), it is by default aligned left, and there is no way to edit the bahaviour. should I use custom css? but what if I want to apply it only to one specific row? a custom css would affect everything. is there a way to get a sort of “extra class” field for every single element?

The funny thing, as I pointed out with no reply, is that I could use the advanced editor, then switch to the wordpress editor and center the element, but if I do it the data will be lost!
Stefano