The EUR/SEK pair is not a major, nor is it a commodity pair. The EUR is obviously a major, while the Swedish Krona is not. The two currencies are closely correlated on account of the strong trade ties between Sweden and the Eurozone.
The EUR was introduced in 1999, as the common currency of the Eurozone, now comprised of 21 countries. In addition to these, there are a few other countries that use the EUR as their de-facto national currency. 6 more countries are compelled by treaty to join the EUR, and indeed, Sweden is one of them. The Swedes have not shown much interest in the common currency thus far, though post-Brexit, many expect the pressure on the country to join the EUR to be ramped up.
The EUR is currently the second most-traded currency in the world, as well as the second most popular reserve currency.
The Swedish Krona was introduced way back in 1873, when Sweden was a member of the Scandinavian Monetary Union. Since then, that union has obviously fallen apart, and the Swedes are in no particular hurry to repeat the experiment. Though compelled by treaty to join the EUR (and not having exemptions such as Denmark and the UK), Sweden has expressed no interest in becoming a member of the Eurozone.
Outside of Sweden proper, the Krona is also used in the Aland Islands, where Euros are also accepted. The Swedish economy is powered by exports of heavy machinery, logging products and cars.
As said above, the connection between the EUR and the SEK is obvious. Thus, the value of the two currencies tends to move in a correlated fashion, meaning that trading opportunities are few and far between. Eurozone instability may offer a chance here and there though, together with Swedish economic performance.