Unassigned Space is mapped and committed virtual memory in use by the process that is not attributable to any particular ...

Unassigned Space is mapped and committed virtual memory in use by the process that is not attributable to any particular image being executed by that process.  Execute Write Copy is memory that can be executed by programs as well as read and written.  This type of protection is used when memory needs to be shared between processes.  If the sharing processes only read the memory, then they will all use the same memory.  If a sharing process desires write access, then a copy of this memory will be made for that process.