This is the IGI record I extracted originally, without the register-only entries added.

Thomas Cavendish m. Anne Curphey 9.11.1839 Jurby

Jane Catherine d. Thomas & Anne Curphey 1.1.1840 Jurby
Anne d. Thomas & - Curphey 7.11.1841 Jurby
Margaret d. Thomas & Mary Anne Curphey 8.8.1843 Jurby
John s. Thomas & Anne Curphey 13.2.1848 Jurby
Robert s. Thomas & Anne Curphey 1.1.1850 Jurby
Elizabeth d. Thos. & Anne Curphey 16.5.1852 Jurby
Eleanor d. Thos. & Anne Curphey 27.8.1854 Jurby
Wm. s. Thos. Anne Curphey 1.6.1856 Jurby
Edward s. Thos. & Anne Curphey 25.4.1858 Jurby
Eleanor Sophia d. Thomas & Anne 5.8.1860 Jurby

The only 5 year gap is where Thomas fits in, in 1845.
The mother is named as Ann in all but one case. She is Ann in all her census entries.

There do not seem to be any other census entries for a third Thomas Cavendish (or Corjeage) born in the IOM in/around 1845 apart from 1881.
I have not found a third Thomas in Jurby in IGI or register, but wouldn't claim to be infallible.

I haven't seen the actual register book for Jurby, only the microfilm of the 'Official Copy'. I'm suggesting the copyist might have made a transcription error, particularly where there is a duplication of names.

On film MIC 65, 20th century Roman Catholic baptisms, I have seen the father of Cavendish aunts & uncles known to me personally, named variously as (Latin version of) Thomas Richard, William Richard and William Roger (!), the correct name, Thomas Richard, being on the birth certificates.