Why does my laptop have a high physical memory despite a few applications?

I am a computer engineer and I will surely help you with your issue. The physical memory is that part of computer which stores the current data on which you are working. The space of physical memory is predetermined at the time of the manufacture. The physical memory is always used when you are accessing any file of your computer and it is used at high rate because the physical memory has to constantly act accordingly with the user input command and the central processing unit for transferring data from user to central processing unit and vice versa.

Hence the physical memory has to be used constantly and its use does not depend on the amount of data you are using.