If this already been requested yet, then please consider this. This would be very useful to recreate the standard related lists “Notes & Attachments”, “Tasks & Activities”, etc. It would only display child records and not parent records. Only templates and not fields as it would be way too complex to try to create a new field renderer for this. The parent record fields can be displayed in template fields. Filters yes on the parent object. Not sure about filtering on child relationship objects. Row actions yes. No to Mass and Global actions. The only decent way I can think of would be to take child relationships from the fields section and make them fully fledged models of type Child. They’d have to show in the page builder UI somewhere and as a child. This could get fugly really fast. Any approach I’ve thought always ends up being messy. Probably why it hasn’t been done yet. Maybe you won’t consider this.