This is one of those areas where you can't really generalize over "Europe" at all since it varies so much between countries. In Scandinavia, the Netherlands and the UK, card usage is extremely high. In southern and eastern Europe, not so much.
In all of EU, 40% of people have a credit card. You're right that it varies greatly throughout the countries.
The highest credit card per capita rate is in Luxembourg, with around 3 per capita (for comparison's sake, in the US it's 3.5 per capita, in most EU countries at 1 per capita).
The highest ownership rate is in Luxembourg, with 87% of people having one. The lowest is in Hungary, with only 9% of the people having a credit card.
Some other countries: Denmark 71%, Bulgaria 12%, Lithuania 16%, Romania 17%. The rest of the EU countries can be seen here, on page 13
http://ec.europa.eu/public_opinion/archives/ebs/ebs_373_en.p...