I have a site that has a load of products which all have the same Product Variant Attribute which is a list of about 50 items all with different prices.

I want to add the same product variants to about 20 other EXISTING products, it seems the only way to do this is to manually go and add the variant to each product AND manually add each of the 50 items manually on EACH product??

Surely there must be an easier way to do this?  As its going to take days to complete and this is going to need to be updated weekly??