Welcome to the Community,
As far as I understand I'll be able to use 64GB of Ram on a Server that has 2 CPUs
The Essentials Kits include licenses for vCenter Server as well as for 3 ESXi hosts with up to 2 processors each. With vCenter Server managing the host(s), you have a vRAM entitlement of 192GB (6 x 32GB), no matter whether the VMs run on 1 or 3 hosts.
If I purchase two licenses of ESXi 5 Essentials Kit, will it double the amount of RAM I'll be able to use on that same server?
No, you cannot combine Essentials Kits. From the EULA (http://www.vmware.com/download/eula/esx_esxi_eula.html)
c) VMware vSphere Essentials and VMware vSphere Essentials Plus
If you have licensed VMware vSphere Essentials or VMware vSphere Essentials Plus, the following additional license terms apply:
VMware licenses VMware vSphere Essentials or VMware vSphere Essentials Plus editions (collectively "Editions") to you solely for managing up to three (3) server hosts and your use of these Editions is limited to servers with up to two processors. For these Editions, the server hosts must be managed by the VMware vCenter Server that is provided with these Editions, and that same VMware vCenter Server cannot be used to manage other server hosts not included with these Editions.
André
