Yes, they are memory logs showing you how much memory a program is allocating/de-allocating after usage. It shows memory allocations at different levels variables, functions, sql queries etc. I remember one time it helped us identifying a certain problem when we were getting fatal errors while running planning engine. It was a problem at configuration part due to which millions of orders were getting generated consuming way lot memory. I don't remember exactly what information helped but I do remember it was these memory logs.
Unless you try to do something beyond what you have already mastered, you will never grow!