Hi Tony,
Yes the William Mayo buried in 1875 does look to be the son of John Totty and Mary Mayo (nee Dear) and the John Jolty (Totty) Mayo buried in 1903 looks to be William's son born 1838 in Newbury. (not sure if he married and I think that he was a Tailor Journeyman)
Here's how the other Mayo burials fit into your family:
Edward Manter Mayo buried 1859 was aged 7 months when he died and was the grandson of John Totty & Mary Mayo (nee Dear) son of John & Sarah Mayo (nee Brown). Edward's middle name should read Manser, this being the married surname of his father John's sister Mary Ann born c1806.
Fanny Mayo (nee Holder) buried 1895 was the 1st wife of John Morris/Maurice Mayo who was born c1857 grandson of John Totty & Mary Mayo (nee Dear) son of John and Sarah Mayo (nee Brown).
Francis Mayo buried 1864 was aged 7 when he died, grandson of John Totty & Mary Mayo (nee Dear), son of William (born c1813) & Mary Mayo (nee Butson).
Frederick Charlie/Charles Mayo was aged 17 when he was buried in 1899 and was the great grandson of John Totty & Mary Mayo (nee Dear) he was the son of Charles Robert & Emily Mayo (nee Palmer) Charles being the son of John & Sarah Mayo (nee Brown).
John Mayo buried in 1895 was aged 79 and was the son of John Totty & Mary Mayo (nee Dear) and husband of Sarah Mayo (nee Brown)
Mary Mayo (nee Butson) aged 64 buried in 1877 was the daughter-in-law of John Totty & Mary Mayo (nee Dear), widow of William Mayo born 1813.
Sarah Mayo (nee Brown) aged 76 buried in 1892 was the daughter-in-law of John Totty & Mary Mayo (nee Dear), wife of John Mayo
Thomas Mayo buried in 1859 was aged 8 when he died and was the grandson of John Totty & Mary Mayo (nee Dear) son of William Mayo born 1813 and Mary Mayo (nee Butson)
Kind regards
Chris
