This is one of my biggest pet peeves in any fantasy writing "I cAn'T lIfT tHIs SwOrD, iT's ToO hEaVy". An average straight sword only weighs about 2-4 pounds and a saber like that probably weighs even less. That stack of books she was lifting by comparison is even heavier that that, probably weighing about 15-20 pounds. This is done way too often and it just doesn't make any sense.
It's exceedingly ironic that the Japanese are so proud of their samurai and katana history, yet due to the draconian laws in Japan, it's impossible for a person to actually own a katana, unless they get an official permission for a culturally or historically relevant one. Forget about non-katana swords because how they could be culturally or historically relevant in Japan for an individual citizen? You'd need to own a museum.
So, it's difficult enough for a random Japanese person to actually weigh a sword in their hands, even their precious katana type. Although souvenir shops sell stuff that look like a sword from 10 meters away, but if I was a serious author, I wouldn't use those things to get the feel for anything.
That being said, any author could google the weight of a sword and then find an object of similar weight and experience how it feel. Easier to go for a trope, I guess.