TL;DR: probably not: they need a lot of calories, and it isn't clear how much farming they could usefully do compared to a group of humans with similar calorific demands.
You might be able to handwave away some of the difficulties if they had access to particularly good crops... things like potato, or sweet potato or perhaps sugarcane, but it bears remembering that quite a lot of agricultural tasks really benefit from having human-sized prehensile appendages and giant sloths seem likely to be ill-equipped in that regard. Nomadic pastoralism might be the only practical solution for them (and even then, they probably ain't gonna be making many dairy products!).
For convenience, lets compare your neolithic giants (which sound a bit like megatherium) to large modern day mammals in the form of African elephants.
Elephants are smaller, of course, and not omnivorous, but they'll do as a point of comparison. Somwhere like Zakouma can sustain a herd of several hundred elephants, which means that your 100-strong group is almost certainly sustainable as hunter gatherers.
If your peeps had a similar diet to elephants, they'd be expecting to eat about 5% of their bodyweight a day as uncooked plant matter... that'd be 35 tonnes of food per day, or the best part of 13000 tonnes per year. According to San Diego zoo, that's the equivalent of 140000 calories per day or 586MJ. We know that cooked food yields more calories though we're not entirely sure how much... somewhere between 10 and 50%, perhaps. That halves the amount of food crops that need to be grown but non-trivially increases the amount of fuel crops that are required, and I bet that while the poop of ruminants can be used as fuel, the poop of animals fed a cooked and processed food diet will be less calorie-rich and therefore less useful as a fuel.
I was unable to find useful food-energy-yield estimates for bronze age farming, alas, but I suspect such figures do exist somewhere.
By analogy though, we can see that the largest cities in the bronze age middle east had upwards of 30000 people. If those people managed at least 1500 kcal per day, then the total food-energy requirement of the city would be ~190GJ/day. The equivalent for your giant village would be merely 60GJ/day,
Clearly sourcing that much food is possible with bronze-age technology and organisation, but a city of that size like ancient Memphis was the capital of a relatively large and prosperous society with a total population well in excess of a million people. Feeding a city without such a large agricultural system around it would be a tough proposition. I can't find a hint of how big the agricultural population needs to be to feed a city, but it ain't gonna be small
Your giants seem like they'd be able to do large-scale agriculture more efficiently than humans (they're their own draught animals, after all) but how much this would help is unclear... you haven't given us anything to work with, and I'm not sure how to go about estimating it. If they were substantially more productive than the equivalent number of humans with the same calorific demands (eg. could one of your giants do the work of 70-100 or more humans?) then it is possible they'd be able to farm for themselves.
What might be easier though is some form of pastoralism where the giants practise a certain amount of land management, but have mobile settlements. As (or if) their agricultural techniques improve they might be able to move more slowly or even settle down, but generating enough calories without some particularly good crops seems like it would be difficult.