This is just the index to the deeds... not just wills, they also cover marriage settlements, property and loans etc, The wealth of informations in the actual books which the index refer to.
While the index can offer clues to dates the actual memorial might refer to something different.
Example. I have a marriage settlement memorial between Charles Creed and Catherine Norris who married in 1778. The index indicates a memorial between Creed Knight. Knight, was the barrister facilitating the settlement on behave of Catherine Norris and her father John Norris, Creed refers to Charles's father Francis. The marriage settlement actually hides a wealth of property transfer, Francis used the settlement to transfer all his land instead of making a will because he knew he had brothers who wanted to make claim on any future will.
There are over 350 memorials with the name Creed as the grantor alone and it took me nearly 2 days in the registry to list them. Goodness knows how many are hiding as grantees. I only managed to transcribe a handful of these over 3 days. Unfortunately there are quite a few Creeds who were barristers who facilitated encumbered estates so quite a few memorials do not refer to family dealings.