Page specific content

I was wondering if there is a way to add page specific content without gaving to fill this in into the tables.

I have 2 pages now and the “test” text is only allowed to show on the left page.
Can I make it so that this text only shows up here but by not having to add this to the tabes?

So basically further customize a page without adding new table entries

Yes, you should be able to control when it appears by using Component Visibility.