I have obtained a copy of the will to a Henry Sherwin dated July 19th 1708, Jamaica mentioned in previous answer to see if its contents suggested it was the author of the tables. Sherwin was known to have planned a trip to Jamaica on a packet boat at the end of November 1705. Since last answer, to date one family of Sherwin has been found recorded at the time from familysearch.org but no mention of a native Henry Sherwin.

Some key points below, parts of the handwriting were hard to interpret and/or text went into ledger gutter. [ ...?...] = undecipherable word or loss in gutter.

- will transcribed into ledger, i.e. handwriting comparison to Sherwin's letters not possible

- lived in the parish of Kingston

- 'That everyone of our principals and correspondents in England be first remitted [...?...] [a]ccording to their orders as if I also [...?...]'

- residue of estate to 'Beloved Brother [gap] Sherwin of Staples Inn London attorney at Law, and my very good friend Thomas Smith [...?...] in Artillery Row of Buttolph bishopgate in London' ..... 'to pay all my debts in England and the residue to be disposed of, according [...?...] Will I made in London November 1705, remaining in the hands of my said brother'.

Notes on will, comments welcomed:
- This Sherwin in Jamaica has well establised links with London, England, i.e. a brother and other contacts - suggesting not native to Jamaica?
- The will left with brother in London November 1705 would fit in well with Sherwin deciding to make a will immediately before his planned potentially hazardous trip to Jamaica at the end of that month.
- Is the London will still in existence, if so, a possible lead. Attempts at online searches have not been fruitful to date.
- Attempts to find packet boat passenger lists at the time to confirm he went to Jamaica unsuccessful to date.
- Is the London will evidence that this may be the Henry Sherwin who compiled the tables, but no firm contents of the Jamaican will to support this.
- My thanks to local Jamaican researcher Ann Marie Lazarus who obtained a facsimile of the will and who provided information on its transcription into a ledger. I don't currently have permission to put the will into the public domain but can email a copy to anyone interested for personal use.