This is the Pay Book of Gunner Charles H. Welsh #335325 who attested on February 4, 1918. His pay book gives his next of kin as his father David H. Welsh, and his mother Mary Ann Welsh, both of Palmerston Ontario.
Charles signed up in Guelph Ontario and a note in his pay book refers to him having deposited a will in Ottawa Ontario in September of that year. At some point he went to England as a page in the book is stamped "1918. Milford Camp, Witley, Surrey"
There are a few loose cards tucked into the pay book.
1. Canadian National Railways showing he is in Lower section of Car E. (no date)
2. Card showing his quarters are on E Deck, Compartment Q and he has one hammock. His mess is in Compartment A2, second sitting
3. A non-personalized standard "goodbye" from Buckingham Palace wishing him a safe return to his home and loved ones, also thanking him for his service. Signed by King George (a rubber stamp)
Thanks to the digitization project by Library and Archives Canada (LAC) we can view Charles' full personnel file online.There we learn that his full name is Charles Henry Welsh and he was born July 1, 1897.
If you are interested, you can download his entire WW1 file.