I've seen Swedish Ph.D thesis while I was postdoc in Sweden: format A5 written both sides with typically 60 pages dissertation + copy of all publications. Students print dozens of their thesis to give to everyone in the lab. They also keep copies to give away during conferences and job interviews.
The experimental part is to be found in the publications section, within each paper. This means the thesis can't contain results that have not been published, or at least submitted to a peer reviewed journal. It puts pressure on a student and his supervisor to publish something in order to be allowed to defend, which avoids having students abandoned from their supervisor and finishing out with no publication (as I have seen in UK). Swedish research groups tend to be smaller than in UK with more interactions between students and the supervisor. It has nothing to do with research secrecy.