A storekeeper at Deptford.
Apparently there were several Tom Harpers, and Pepys doesn't help us much with identification.
There was a Tom Harper who gave Pepys political news on 9 Feb. 1660, but L&M's index volume gives no citation for one on March 3, 1660. Another Tom Harper, a Deptford storekeeper, doesn't appear until 1667. -- L&M Vol. 1, index, companion volumes.
Chart showing the number of references in each month of the diary’s entries.