Thanks gadget
It is speculative but the Ps may be Mrs Alice and Mr Albert Woodward Parry (1834-1894), and family of ‘Airedale’, Carnarvon Road.
The diarist wrote that he was 'Amused at Ps remarks about C.' C was an architect.
Albert would have known the diarist's boss, C. well as Albert was an architect, and Reading borough engineer and surveyor 1871-1891.
BTW I have identified these C19 central Reading street names; Abbey Square, Abbey Street, Abbots Walk - they are all very close to the diarist's office (Blagrave St) and digs (Forbury).