I would suggest you to open a case to Cisco.
They will be able to check for know bugs on your IOS version and will ask you configuration details that you may don't want to publish here. (but if you want you can put the result of a sh tech somewhere it could help us)
Also doest it append after a reboot or did it start to get corrupt after a long uptime ?
Without the service console you need to use vCLI. It works with ESX/ESXi hosts.
Right now, I can't find a documented way to clear the ARP tables via RemoteCLI. The best I can find is here: Top Five New vCLI commands in vSphere 4.1
list all active connections: esxcli network connection list
list all ARP table entries: esxcli network neighbor list
Hope this helps. Let us know what support says.
Best Answer
Then it's autorefreshing. :-)