Archaeology was a booming field in Britain throughout the 19th century, being a fashionable pursuit for predominantly upper-class individuals. Many private collections were started, and most of the great museums were founded during this time. Egyptology in particular struck a chord with European society at the time.
Just have a look at https://en.wikipedia.org/wiki/List_of_museums_with_Egyptian_... to get an rough idea of the extent of Egypt-mania in Britain; the 'UK' section dwarfs the others! So although that quote is rather vague, I strongly suspect that it is simply referring to the large quantity of Egyptian artefacts that were being excavated and moved to museums in Britain, especially after Epypt was annexed by and amalgamated into the British Empire in 1882.
Just have a look at https://en.wikipedia.org/wiki/List_of_museums_with_Egyptian_... to get an rough idea of the extent of Egypt-mania in Britain; the 'UK' section dwarfs the others! So although that quote is rather vague, I strongly suspect that it is simply referring to the large quantity of Egyptian artefacts that were being excavated and moved to museums in Britain, especially after Epypt was annexed by and amalgamated into the British Empire in 1882.