I'd take the Arlanda Express and then a cab to Grand Hôtel Stockholm:
Grand Hôtel Homepage
Enjoy a traditional Swedish Smorgasbord (SEK 380) while enjoying the view of the Royal Castle and Nybroviken just outside your windows.
From their homepage:
The Veranda serves a very popular Swedish smörgåsbord. As the only restaurant in Stockholm that offers a smörgåsbord all year round, we strongly recommend our foreign guests and visitors to try out this Swedish tradition. All the classic Swedish dishes that are traditionally included in a smörgåsbord are there - and a few more.
A staple on the smörgåsbord is the herring, with which a Swedish snaps is a must. What, then, could be better than the Grand Hôtel's own 1874 Grand Aquavit, which was produced for the hotel's 125th anniversary in 1999. We are all very proud of this homemade aquavit, which is gently flavoured with cumin, aniseed, fennel and a dash of sherry, which creates an especially smooth, full and balanced taste.
The Swedish smörgåsbord is the fruit of a long and proud tradition. Permit us to suggest how best to enjoy the wonderful smörgåsbord:
1. Think of the smörgåsbord as a four to six course meal.
2. Do not overload your plate. Make several trips to the buffet and take a new plate each time.
3. Begin with the herring dishes. These are traditionally served with boiled potatoes, crispbread and cheese. Herring tastes best with a cool aquavit chased with cold beer.
4. Next, try another Swedish speciality, gravad lax, which is served with a mustard and dill sauce. Try the smoked salmon also, and the eel, perhaps with a few drops of lemon.
5. Then we suggest a variety of salads, egg dishes and cold cuts of meat and poultry.
6. Now it is high time to try the hot dishes. Don't miss the Swedish meatballs with lingonberries.
7. To round off the meal, we suggest our famous desserts, especially the fruit salad, which is popular with many regulars. A cup of coffee and an iced Swedish punsch completes the meal.
The smörgåsbord at the Veranda is undoubtedly very tempting. Choose carefully to make sure that you sample as many delicacies as possible.
Skål!
The Smörgåsbord is served:
February 27 th - April: Weekdays 6 pm - 10 pm, weekends 1 - 4 pm, and 6 - 10 pm.
May - August: Weekdays Noon - 3 pm, 6 pm - 10 pm, weekends 1 - 4 pm, and 6 - 10 pm.
September - November until the Christmas buffet starts: Weekdays 6 pm - 10 pm, weekends 1 - 4 pm, and 6 - 10 pm.