is there a method to flush the memory off the serial monitor so as to prevent it from using too much memory off my RAM?
Your PC is running out of memory?
while using task manager, I see the serial monitor continuously using up more and more memory in the processes tab... anyway to stop that? or reduce that?
Not that I know of. Perhaps reduce the amount of text that you send to it.
The serial monitor does have a maximum buffer size, and once it hits this size, it will grow no larger (instead, dumping old data in the window as new data comes in). This max buffer size is relatively large with respect to occasional serial data coming in, but it shouldn't cause any sort of memory issue unless you are working on a seriously memory constrained computer.