This name is on the St Mark's War Memorial, Kennington Oval, London SE11
J. B. Maffei
(John Maffei)
This is a tentative identification as I cannot find this name in any of the online military databases.
Information from the 1911 census
A John Maffei, born in Italy but a Swiss national, aged 28 and working as a restaurant waiter, was living with his wife Florence, 23, born in Holborn, at 122 York Road, London SE1. There were no children.