Can Silver plating be done on Copper utensils?

A. Hello, firstly, you're lucky. Yes copper can receive a silver or gold plating. But the process will depend of the use of your tumblers. If it is purely decorative, it's a bit easier.
The preparation is essential; hopefully, there are many common processes to prepare copper based alloys. Then you have to know that silver will probably turn yellow with time if it's plated directly on copper. So I recommend you add a nickel diffusion barrier that will reduce or stop the atomic migration between copper and silver.
Silver and gold plating both use cyanide-containing electrolytes. So you need to be really careful.

If your application is for food use, as I can remember there a specific operation to neutralise cyanide. But I'm not competent enough to inform you about this.

A. Hi Sunny

Tableware has been silver and gold plated since the nineteenth century. It is very well established technology with well known characteristics such as plating thicker where there is wear - eg the lip of a cup. This is very important with a high cost material like gold.
If you are going into manufacture the numbers involve will rule out amateur plating but there are many companies specialising in replating tableware for the high end hotel trade and they will be happy to advise.
Please be clear to them if your items are decorative, requiring only a "flash" of gold or intended for regular use where the thickness and cost will escalate dramatically.
Two technical points. You cannot use nickel as a barrier layer due to the possibility of nickel allergy.
Although cyanides are used in some processes, none will be present in the final coating.

Your business plan should provide for the wide fluctuations in gold price. It is very easy to pay a fair price for plating only to find that the value of your stock has fallen a month later.