I can see a lot of 'Slavic thinking' with regard to hospitability in Sweden. I think it's because of the climate, as most Slavs live or lived in areas where distances were large and the weather harsh. Also there is very different mentality between Scandinavia and Germany. In Denmark they call it 'tribal society' because people are closely bound by being Danish and if you look different and were born here, you might still be treated with some kind of reserve, it's not offensive or anything, though, but you still are "not a real Dane". Even people from Southern Jutland are characterized as Germans sometimes, but I suppose the situation I know was just picking up on somebody from there. Also in Denmark it is important not to show you are better or think so, with regard to others, you need to be a bit humble to gain respect, and 'a bit' means a lot here. This is different than the UK for the most part or the US, but similar to Poland (my home country). And with regard to social thinking Scandinavia is somewhat similar to Russia (maybe not Russia recently, but in the old days most people lived there in small farming communities helping one another and doing social work).
On the other hand the difference is that in Scandinavia people care about making things in order and planned maybe more and that they are less warm to strangers (a 'hospitality' thought: they are not showing emotions to strangers but still 'inside' they are no different with emotions). And everything is more formal, including hospitability in sense of meeting arangements - you need to be on time, no be rude, say thanks - but that's nothing new, really. People also say that Scandinavians are not spontaneous and there is something in it, but it's more about that they need to plan everything and it takes time in my humble opinion.
In the end, I would like to say I have been living in the US, UK, Poland and Denmark and I see that Denmark-UK or Denmark-US in terms of 'mentality' differ like Poland and Denmark. Different Slavic nations have emerged as tribes in modern locations some 1500 years ago. This is when things separated between them. At least 4000 years ago or before Indo-Europeans have conquered Europe. Indo-Europeans means among others those who gave rise to Slavic and Germanic peoples' languages and culture. Indo-Europeans already had their own culture and religion, but because of this amount of time lapsed no-one asks about 'Indo-European mentality' and the question is similarly without and answer with regard to 'Pan-Slavic-mentality'. You can group South (Western and Eastern), Western and Eastern groups and then you are able to say something about the mentality of each group (maybe) and how it was shaped thanks to, among others, historic records, but not about Slavs as a whole. I believe the group is too diverse for it to be meaningful. And we have no data on early Slavs in an amount which would suggest their customs, religion and the point of view, like we have with e.g. Romans.
Although Sweden is a largely egalitarian and relaxed environment, hospitality and eating arrangements are often a formal affair.