8 hour Layover in Stockholm

It doesn't sound crazy at all. The train takes you to central Stockholm in 20 minutes. I assume this is an arrival from North America and a departure later to Munich? Is it one ticket or are you self connecting (i.e. do you need to check in again for your second flight)?

What are you interested in? It should be at least time for a walk around the city and see a few sights.

I am flying Chicago to Stockholm then an 8 hour layover from 0720 to 1520. Then onto Munich.
Probably just catch the train to the old town.
Any special food to eat in Sweden?
Would like to see Abba museum but probably too far.
Are there any Covid restrictions if fully boosted in Sweden? Any passenger locator forms?
Thank you.

This says rules will change (presumably loosen) April 1

https://www.krisinformation.se/en/hazards-and-risks/disasters-and-incidents/2020/official-information-on-the-new-coronavirus/travel-restrictions

(I know the link says 2020, but on the page itself, it notes that it was updated earlier this week.)

I'm not up to date with the latest restrictions, but as long as you are fully vaccinated you should only need a proof of vaccination I think.

If you want to see the Abba museum, it is certainly possible to spend a few hours there. It is a 10 minute tram ride from the central station.

For a place to eat lunch in Gamla stan I'd recommend Slingerbulten at Stora Nygatan 24. It was one of my favourite places for lunch when I used to work in the area. They serve well made traditional Swedish food at reasonable prices. So a great place if you are looking for potato pancakes, pea soup, fried herring. Or of course meatballs.

Zero travel restrictions to Sweden from April 1. Since you arrive early, the old town is a good start. Express train+a short walk would be my preference. From old town you can go by ferry to Djurgården and ABBA museum. I guess pre-booking the museum is a good idea.