Translation:They are eating dinner in the meantime.
It was bothering me that "middag" seems like it should mean lunch (after all, it looks like "mid-day"). I did some research and have read that "middag" is a meal eaten around 4:00- 5:00 in the afternoon, and then "kveldsmat" is a later meal taken at around 8:00. This makes sense based on the analysis of the two words, but can a Nordmann confirm? (Also, if it's indeed true, Duo should teach "kveldsmat" as "supper").
frokost = breakfast
lunsj = lunch
brunsj = brunch
middag = dinner
dessert = dessert
kveldsmat = supper
nattmat = late-night snack or full meal
mellommåltid = any meal in-between the regular meals
"Middag" is the meal eaten in the middle of our day, the majority of people just don't get up at four to tend to the livestock anymore. ;)
Yes, eating at 6 or even as early as 4:30 pm is commonplace here. It all depends on your job and family arrangements, of course, but there's a general trend of eating earlier.
Norwegians also tend to have a lighter (cold) lunch than is the norm in many of the countries that have dinner later in the evening.
"Middag" is understood as a the large, savoury afternoon/evening meal between lunch and supper, and is the main meal of the day. Your dinner should fit the bill, even if you might skip supper afterwards. :)
Late answer for Jared, but someone else might find it helpful:
frokost = breakfast = depends on your work day/lifestyle, but usually eaten early, around 6am-7am
lunsj = lunch = also depends on your job, but I've known Norwegians take their lunch as early as 11am. 1pm would be considered late by many people. NB, Norwegian lunches are usually quite light and plain, often 'en skive med ost' or similar.
brunsj = brunch = similar to elsewhere, around 10.30am-11am-ish
middag = dinner = eaten quite early (again depends on your personal circumstances), from around 4.30pm-6pm. This is the main meal of the day.
dessert = dessert = any time :)
kveldsmat = supper = 2 or 3 hours after your main meal (so around 8pm or 9pm), and usually very light/small portion of something.
nattmat = late-night snack or full meal - think a takeaway on the way home from the pub at midnight/early hours - kebab, pizza etc (varies by region what is typical).