The CPU that you have, Intel Kentsfield Q6600, is not officially supported for ESXi 6.5. Its closest Kentsfield Xeon equivalent X32xx series is also not officially supported for ESXi 6.5.
https://www.vmware.com/resources/compatibility/detail.php?deviceCategory=cpu&productid=9&deviceCategory=cpu&details=1&cpu_series=9
So you are pushing your luck with trying to run ESXi 6.5 successfully on a very old CPU architecture (around 12 years old). The Kentsfield CPU does not have Extended Page Tables (EPT) feature and thus its virtual RAM will be managed by the hypervisor instead of by the Intel CPU VT capabilities and thus resulting in slow VMs. ESXi 6.5 dropped support for many CPUs that don't have the EPT feature.
It looks like the VMware Tools you have is 10.2.1 (10305) which have SVGA 3D driver version 8.15.1.60. You could try updating the VMware Tools to 10.3.2 which has SVGA 3D driver version 8.16.1.0. VMware Tools 10.2.5 has SVGA 3D driver version 8.15.1.65.
https://my.vmware.com/group/vmware/details?downloadGroup=VMTOOLS1032&productId=614
You could also try reducing the screen resolution so that it will use memory.
But if the crashing problem is related to the unsupported CPU, it looks like you may not have much choice. The latest ESXi version you could probably go with based on Kentsfield Xeon is ESXi 6.0U3 or you should be looking to upgrade to newer hardware.
These lines in the vmware.log does not look encouraging.
2018-09-13T14:11:20.419Z| svga| W115: MainMem: Failed to map physical memory [517628,517632) 4 ranges, 'Out of memory' (bad0014).
2018-09-14T05:16:37.232Z| svga| W115: MainMem: Failed to map physical memory [321162,321163) 990 ranges, 'Out of memory' (bad0014).
2018-09-14T05:16:37.637Z| svga| W115: MainMem: Failed to map physical memory [35987,35988) 992 ranges, 'Out of memory' (bad0014).
2018-09-14T05:16:55.497Z| svga| W115: MainMem: Failed to map physical memory [439790,439791) 1817 ranges, 'Out of memory' (bad0014).
2018-09-14T05:16:55.498Z| svga| W115: MainMem: Failed to map physical memory [439790,439791) 1817 ranges, 'Out of memory' (bad0014).
Without EPT in the CPU, it will be up to the hypervisor to map the virtual RAM of the VM to the actual RAM in the hardware and these errors seem to show ESXi 6.5 is failing (for whatever reason).