If you want to find out what's using committed memory you need to look at Task Manager's "Details" tab and enable the "Commit size" column.

Nor will the total of the "Commit size" columns add up to the "commit charge" (30.1 GB on your machine), because other things contribute to commit charge: Nonpaged and paged pool and some more "subtle" mechanisms like copy-on-write sections, pagefile-backed sections, AWE mappings... but these are usually small compared to process-private v.a.s.)

On that tab, the "Memory (Private working set)" column corresponds to what the "Processes" tab shows for "Memory". This is the RAM currently assigned to each process for its committed virtual address space. The remainder will be in the pagefile. But, again, processes have other types of address space, mostly of the sort called "mapped", and some fraction of that will be in RAM as well. There are other system-wide things created by the OS, not specific to any process, that use up RAM too.