It’s all about damping. To solve this in our current game (we have small physics objects in animating drawers) I set the objects linear and angular damping to a number that gave me results I was happy with. However if you are moving the the trolley quickly over a large distance this will probably not work as well for you.
I would suggest looking at Physical Materials. You could fake the physicality of the trolley and give it very low friction and restitution, which prevents objects from sliding or bouncing off that material, then overriding the combine modes to use the min value.
The other thing you could look into is the mass of the objects, even if that means changing it when putting the object into the trolley (I’m assuming that objects are placed in the trolley?)
Physics is hard, especially interacting objects with each other, I’ve always solved it through trial and error and never found a one size fits all solution.