Issue: For normal (non‑admin) users, the table has been hidden from the left‑hand navigation by revoking its List permission, but now the table detail grid no longer appears in the master‑detail view on its parent pages. As a result, users cannot add or edit notes via the embedded subgrid even though they still have Access, Add and Edit rights through the Advanced Security window.
I think for such case, then you still need to give List permission for the detail table to that users.
If you want to hide it from the left-hand navigation (Sidebar), then you may use MenuItem_Adding server event.