But why would his puzzle game collection waste someone else's time ? He's the one collecting the games or doing the puzzles so why would it waste anybody else's time but his ?

Because his puzzle-games collection are computer games you can play yourself, they can be found here: https://www.chiark.greenend.org.uk/~sgtatham/puzzles/ Or in the appstore/playstore.

My current timewaster is 'patterns',a nonogram puzzle

Interestingly, I JUST finished reading (many years after it was published) The Player of Games written by Iain M. Banks. In it, there is an orbital habitat named Chiark.

I assume that the interest in games and the hostname of his webserver are very much related.

The server is named after that orbital habitat, but not by Simon - it's someone else's webserver.

He has a collection of puzzle games you can download and waste time playing.

Gee, thanks :D. I didn't know that at all and the article has no hints about that. I came to that possibility but it was reaaaally out of context and off without prior knowledge. Thanks for confirming it, I really didn't understand what was what. edit: I took a look at the page again and there are no links or mentions of puzzles or something, I knew I wasn't crazy (or that dense) !

The hint is clearly in the sentence you're confused about -- that he has also created some puzzle games is the only plausible explanation.

FWIW, the first explanation I thought of was something like "he replied to people asking for help that he was busy doing some (jigsaw) puzzles and wouldn't answer for now, thus wasting people's time by playing with his puzzles rather than answering". edit: and by puzzle I meant that kind: https://en.wikipedia.org/wiki/Jigsaw_puzzle. Puzzle in my mother tongue is the word used for jigsaw puzzles. Other puzzles are called "brain teasers".

ooh, that would explain why there was a small but steady stream of people posting jigsaw related stuff in rec.puzzles back in the usenet days!

-- that he has also created some puzzle games is the only plausible explanation.

Nowhere there does he claim authorship, merely possession of a collection. Without knowledge of his webpage or the games, there is more than 1 logical conclusion.

It's in a postscript attached to a sentenced about how giving away software is what helps him sleep at night. I'm not sure how you can reach any other logical conclusion without throwing out data from the article in favor of completely off-topic items.

It was implied. You don't need prior knowledge to deduce it, except the knowledge to ask the questions you wrote in your other comments.

Are you implying I am stupid ? /s