They seemed a bit big to me too. Although I’m not sure to what extent that’s colored by modern interpretations.

When I was a kid and had encountered less fiction, the image of trolls that popped into my head from the Hobbit was more like Ogres in Warhammer, Warcraft, or DnD (the portrayal is pretty consistent, something like an enormous, crude, gluttonous man-like thing).

Nowadays trolls tend to be portrayed one step further toward the animalistic side. Even in the Lord of the Rings (as distinct from The Hobbit) they’d gotten a bit more animalistic IIRC (then again, I need to reread the books, this might be colored by the movies).

There are very few descriptions of trolls in TLOTR. The troll that the Fellowship encounter in Moria has "a huge arm ... with a dark skin of greenish scales [and] a great, flat toeless foot". The mountain trolls who are intended to wield Grond in the siege of Minas Tirith aren't described at all.

None of them are anything like the vaguely comedic trolls in The Hobbit.

Interesting! I’d forgotten and, I think, entirely substituted in the movie version.

I thought the trolls were perfect. Big, unkempt, medium drunk. They should be a great deal bigger than Bilbo.

Ye reading some background it is the classical view of trolls as like big humans?

I mean orcs are wretched elfs so it makes sense to draw them very human in some sense.

I think my view was very much inspired by DnD. It is interesting to note how different this stuff were viewed at the time.

Trolls, like Jotun, can be both monstrous or humanlike. In Scandinavian folklore a troll is more of a broad category than a specific 'species'. The main thing is that they are malevolent and supernatural. Some trolls are grotesque creatures with a dozen heads, while others are so human like that they can exchange their children for human children without the human parents ever realizing. Following is from a Danish historic dictionary:

«1) according to folk belief: a supernatural being hostile to humans (dangerous) (of a more or less human-like form), especially of supernatural size and strength, ugly (creepy) appearance, thought to live in hills (mountains), forests, etc. (cf. Hill, Mountain, Sea, Forest troll and underground); also of smaller beings such as dwarfs or gnomes (Junge.308. NPWiwel.NS.22. Feilb. cf. Small troll)»

Just from reading the text itself. I’m well familiar with the D&D troll, but Tolkien’s trolls are just big ruffians covered in mutton grease.

For what it’s worth I personally read The Hobbit for the first time as a child a few years after watching the first Harry Potter movie.

So when I read The Hobbit I imagined the trolls to be similar to the giant troll from the first Harry Potter movie. The one that goes after Hermione when she’s crying in the restroom and then Harry and Ron have to save her.