You’d need to plug that charger into some kind of balance circuitry for it to balance all the cells or parallel groups individually. The 36V vs 42V is just the ‘nominal voltage’ vs the fully charged voltage. Most cells are ‘nominal’ voltage of 3.6 or 3.7V per cell so 10 in series is 36V (or 37V depending on the specifics of the cell might be +/- a volt or two from here), this is where they are at 50% basically or what voltage you can expect out of them for most of the discharge.
Regarding amperage it is the limit on how quickly you can charge this is also typically capped by the 1C (or 1 times the Ah rating on the battery for charge rate, say you have 2.5Ah battery you should only charge at 2.5A at most, if you put two in parallel you can double the rate since it gets split between the parallel packs.
Most people using lipos I think use the imax b6, I’ve used a few chargers from keenstone that I like (they have a 500W one but only has DC input so need to have some kind of AC->DC transformer still before the charger). For li-ion I think the tendency is to go with a BMS (bestech is a good brand from what I hear) but you can search for 10S balance chargers as well. Advantage with balance charger vs BMS is less crap on the board to potentially fail, advantage of BMS is easier to charge once you’ve set everything up.