Load Terminal ideas

Those terminal can be programmed/selected to be switched terminal. For example they can be used for turning lights on and or off according to sun light and some even have a timer. Used as a night light for example. Or used with sump pump, where the sump pump is allowed to pump and is disconnected when the voltage gets to low...but usually this needs a relay or contactor to handle that amount of amps.
Some terminals depending how they are set up can disconnect the power when the battery power is getting to low so the battery is not being killed of low voltage.

Actually most folks do not use those terminals.
Most will hook their devices straight to the battery.
Never hook a inverter to those terminals because they could over load them and burn them up.

You do realize, that your inverter will pull 83 amps at 12 volts when fully loaded.
Your Battery is to small to do that if I remember right....It can handle about 20 amps without being damaged in the long run.
Your 100 watt panel is most likely to small also .....this size battery should be charged with a recommended 11 amps or a bit more. 5 amps will do if your load is small but will take longer to charge the battery.
If you take 50 Ahr out of that battery for example, which is the max you should take out of the battery,
it will take about 130% to charge it up again or 65Ahr.
That means that you have to put about 900 watts back or in other words, you need to charge your battery 2 full days in summer and more in winter under full sun without any load applied to the system or battery if using the 100 watt panel.