I have a windows process whose virtual size is far too big for what it does (26gb) I've used VMMap to map out how the memory is laid out and I've gotten the address of the private data, which is showed as reserve.
How can I view what's in there? Is it even possible
This application is probably leaking memory. If it is so, then memory consumption will indefinitely grow with time.
If you are the developer, then you can use memory profiler to find out what objects are not released by application and who is holding them.