I had a short look at it. It's a little hard understanding the handwriting, but the language is clear enough.
The letter is from your great-grandmother. She's telling your grandfather what the people back home are doing.
There is a mention of King Haakon near the top of the second page, though I don't fully understand what's she's writing. Either the king, or a ship with his name, were coming from Kristiania (the old name for Oslo) the day before, and leaving for Bergen, where there's an exhibition starting today. It seems like �yvind were onboard, and possibly a friend (Thoralf ?) were buying him "dram og �l". (Dram means akevitt or something similar, �l means beer.)
I can try and translate more later perhaps.