Paul's Lunch

He opened his book revealing four columns with, in order: a name, place, date and then another place. That was it. The paper rustled with age as he turned the pages, there were hundreds of lines filled in, all in different pen but the same neat handwriting.

"Some tek something. A souvenir. Some leave somethin' behind. A callin' card. This here could've bin me downfall, was me one mistake if you like. It'd give us away. They're all in 'ere."

At this stage I still hadn't worked out quite what he was showing me.
Or what he was telling me.