Easiest way is to invest in a router that has robust traffic monitoring and analysis features. Assus routers specifically having the Traffic Analyzer feature are popular around here.
Barring that you can install traffic monitoring programs such as Glasswire on each device.
I personally use an ASUS RT-AC3200 router having the Traffic Analyzer feature. It provides a good overall breakdown of usage on a per device basis. But I'll also use Glasswire in conjunction with it once I've determined a problem device - Glasswire allows seeing more speicifc detail at the device level.
Our page at account.viasat.com will show current usage and you should see the prior month. Unfortunately that's all we're able to do but there are some 3rd party tools that will give the breakdown you're requesting