As a Canadian, what are appropriate gifts to bring when travelling to Europe?

Personally when I give "Canadian" gifts to my friends out of the country its maple syrup inspired things (candy, bottles, etc) or Ice wine as thats pretty unique to Canada. Ice wine isn't the cheapest thing to buy for a friend so it depends how good a friend we're taking about. Its usually $60 to $100 a bottle but theres a decent selection at duty free in the Canadian airports like Toronto, Ottawa, or Vancouver. The maple syrup thing works well with my european friends. Small bottles shouldn't cost all that much, check local grocery or even at the duty free again. We're talking like $10 - $15. If you want something uniquely Canadian though, perhaps some native gifts or art. Oh, and ketchup chips are a thing in the UK.

I remember a whole range of maple sirup items in shops, like boiled sweets. These will travel better than bottles.

What I like to bring home from a country, which I think is also a nice gift, is small calendars, the ones with pictures.
No need to go for bigger than post card size, if you can find them so small. Not to eat but to consume over the next year even so. And they make a nice reminder of your visit.

Good places to go 'souvenir hunting' are the shops to museums and (National) parks. Specially those that are about the history of Canada.

For starters AirBnB people are not "hosts", they are essentially hoteliers, renting you a room (often at market rates) and not really deserving of gifts any more than a guesthouse owner (unless they something extra, like drive you all over the place for free).

But rather than bringing a lot of cheap shelf candy to give out along the way, you might consider bringing just a couple of nice things for folks who make your trip super special.

what i would love if i was your host/hotelier/renter?

• Some sort of weird, local / regional / national sauce. As an example, i haven't been able to find uk's / ireland's mint sauce in spain, and i love putting mint in things. syroup will do fine.
• A local / regional / national recipe book ( this migth be weird if the host is young, but, hey, it's about food and food's an international, worldwide necessity and pleasure).
• A local / regional / national "book of cool pics from x" , those usually sold at tourist stores / postcards.
• Some local beverage / Liquor.
• An invitation to get the experience back if he wants to, by being your guest in the future at your place's spare room ( this is weirder if done on arrival and not on exit or after some ... human contact).

As a Greek, I buy magnets for the fridge, as described here.

Notice that I do that regardless of whether my trip was to America, Europe, Africa or Asia (list of destinations). All the magnets I have bought live in Greece.

Notice that this little (easy to carry) can be very special, for example one bought from Monaco was like a wall-frame, made mama smile wide! ;)

Moreover these little cuties can be helpful, since my parents use them to hold notes, cached telephone numbers, etc.!

My father, when in Canada, he brought back home jewelry for my mother. One shaped like the leaf in Canada's flag was very distinctive, and favored by my mother. He also brought Niagara-falls-related stuff, which I don't really remember, except from the classic photo.