Every single time I open a table that has foreign keys, the related tables open up as well.
Even after hiding it, it pops again every tiem.

I don't think it should be enabled by default:
* It takes up half of the screen real-estate
* The title mixes up the two table names, which is confusing, especially if such a table name exists.
* It's not obvious how to dismiss the related tables. A close button on the top-right of the related table would be more intuitive.
* A table can have multiple related tables but it will only display one of them

Please give us an option to disable it, and consider disabling that feature by default.