The most recent UK shooting of note, Derrick Bird, used a double-barrelled sawn-off shotgun and a .22 (bolt-action) rifle. Would it have been worse if he'd had handguns and semi-automatic rifles? We'll never know, but he did try to acquire another firearm mid-rampage so he clearly felt like he needed more firepower.
I'd agree that Scandinavia has a bigger problem (EU would be at 2 without Finland). (Norway is not part of the EU, and I also didn't count the US soldier going on a rampage in Afghanistan).
Of those mentioned in the list; 6 in the past 25 years are in Europe. 3 shootings, on this list alone, happened in the US in the past 6 months! Most European countries probably haven't had any of this type of thing happen in the past 25+ years.
It certainly looks like Scandinavia and the UK might have a problem. Europe as a whole still has fewer than the US for a similar population but it is high. None for China, India or Brazil. So it is not just about normalisation...