This is an expression related to conveyancing (the contracts associated with buying and selling property, i.e. real estate), in the UK. Conveyancing is done by solicitors (lawyers who do not usually appear in court). Its meaning is not predictable from the individual words.

The Land Registry is the state registry of property (real estate).

"Office copy entries are certified copies of the land or charge certificate, obtained from the Land Registry, confirming ownership of a property.
An office copy entry is officially known as an Official Copy of Register of Title – and also a title register – and, in effect, is the certified, modern equivalent of the old Title Deeds, physical documents which were used in previous times to prove property ownership and show the ownership chain. In effect it is a snapshot of the details pertinent to the most recent title deeds relating to a particular property which is normally ordered by a vendor's solicitor to passing onto the buyer's solicitor for perusal. It is normally always accompanied by the Land Registry Title Plan which shows the general position of the property."
https://www.samconveyancing.co.uk/news/conveyancing/office-c...