Sweeping generalizations are almost always wrong, weight can be factored by previous injuries not everyone is in the right condition to do things might not have full range of motion ect.
As for a week, I've been weight lifting consistently for 5 years and I still find uses for the 10 pounders. Have used them as work horses for high reps but they're great for working on form when I'm trying to incorporate a new or unfamiliar move I want to add to my routine.
Also over the years I've found I can't go a few days or a week without losing some shape if I don't do anything I won't be able to do a full work out I'll have way less reps and sets and it's just torture getting back into form. If I don't feel like working out I can just cheat and grab the 10s and do something quick and easy and it is usually enough to keep me toned/firmed up for when I'm ready to start up again.
I made the generalisation because it is pretty easy to do so when we're talking about 10lbs. Not factoring in disabilities, injuries, or endurance training, you will neither grow bigger or stronger with 10lbs dumbbells. I can see using them for some shoulder exercises
as a warmup, but otherwise, no one has grown from lifting 10lbs. Or as Hulk said in the Avengers movie "Puny Weights!". Well, something like that.

Also, and this is only because it's a pet peeve of mine, there is no such thing as toning up muscles - not through exercise at least. It's a myth. You can only 'tone' (i.e. lose body fat) your body through a caloric deficit. When working out, you will either grow in strength or size (size or strength gain), to different extents in both, or you don't grow at all. That's the only way one can 'tone', by losing body fat and putting on muscle, or for anyone whose not a veteran in lifting weights, it's not really possible to do both simultaneously(unless you're a newbie making what are called newbie gains). So you either bulk or cut, not tone. Toning is usually used in the context of doing high repetitions (20+) to somehow remove fat and tone the muscle - pure broscience.
I'm sure you know this, since you've been working out for 5 years, but other people may not.