If you are GST/HST registered, you can indicate in your listings that GST/HST will apply to Canadian residents and they should wait for an invoice (including the tax) before proceeding with payment.
No, there is no tax table available for Canadian provinces on eBay.com, only on eBay.ca
I am not sure why you would want to list on .com unless you have used all your "free" listings associated with an eBay store on eBay.ca