Different monitoring apps tend to assign power usage differently between apps, services, the screen, etc. But the display is usually the biggest single power drain, so unless you've only had it on for a short time I'm not at all sure that there is any problem here. We'd really need to know more about your usage to say anything, and more about the device and usage to say very much.
Turning brightness down is one way to reduce power usage by the screen. Turning the screen off when not in sure (or using a shorter timeout period) is the other. That's about it really.