Table and Grid layout

In these layouts, we can use the same UI as the full-screen editor to toggle the visibility of the Inspector panel:

List layout

In List layout it feels important that the preview remains visible. Instead of exposing a dedicated panel, the Inspector contents are loaded into the content frame via drilldown pattern:

This feature would be equivalent to the quick edit experience in wp-admin:

Original issue

Inline editing has considerable overlap with quick-actions (https://github.com//issues/55096). For example most quick-actions for pages (https://github.com//issues/55628) could also be accessed by clicking on values in the table directly. So for the initial implementation we might reuse where possible. Hopefully this mockup captures that:

Incidentally the "Author" menu in the above concept should be virtually the same as the one that has already been implemented for filtering, so hopefully some legwork is already done 🤞 :

One exception we might make straight away is boolean values, e.g. whether comments are enabled or not. In this case the cell can probably contain a Toggle.