What is this table using for?

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Hellow..

can someone please tell me, what this table using for? it's always empty

1. BlockRelation
2. CollectionVersionAreaLayouts
3. CollectionVersionAreaStyles
4. CustomStylePresets
5. CustomStyleRules
6. LayoutPresets
7. Layouts

i know the name describe it, but when it used?
i have ENABLE_CUSTOM_DESIGN == false in site.php

Thanks.

fastcrash