Swap usage occurs when the device is running out of physical RAM and has to use virtual memory. Some swap usage is normal and nothing to worry about; you can check in Reports > System > Swap Usage to see if the amount of swap you're using is typical for your environment.
The most common cause of high swap usage is your application configuration. Virus Blocker Lite and Phish Blocker run at roughly 1 GB of RAM for just those two apps, so if you're using the full version of Virus Blocker and don't have an on-premise email server, those are great first candidates. (Especially if your device has only 2 GB of physical RAM.) Please refer to this article for more guidance on applications & memory usage: Reducing RAM Usage
You might also try bypassing any traffic that doesn't need to be scanned to try and limit the amount of traffic that's being processed: How to bypass traffic from filtering
(Traffic that probably doesn't need to be scanned includes network printers, VoIP phones, PoS terminals, Internet of Things devices like smart light bulbs or speakers, &c.; as a general rule, anything that doesn't have a web browser.)Follow