As for .csv import, I guess, Xap1 is right. As for his comment on following that format for importing the product, I guess it will be first of all time-consuming and secondly, it can mess up your data.
I can offer you to do custom options import via the application called Store Manager for Magento. The file for import should contain SKU of the products, their names, prices and other related data. The example of the file you provided can be imported via the application.
There is 2-weeks free trial version of Store Manager available for download here:
In case, you need to do import only once or a couple of times, you can use trial as it fully functional and you will not to pay any fee. So in any case, you can give it a try.
I can say that his kind of import can be not very easy. I need a lot of additional fields to add. Tried this extension and everything become simple. I created many fields and can create more.. Really good.
Hi Muk, I hope you found your way already without the paid extensions because there is no need to pay for extensions to do this. Surprisingly, it\’s not very known, but if you haven\’t heard Sourceforges Magmi (Free Magento Plugin) can do custom options and much more. Setting it up is far easier than pragmatically doing it - it will import faster and much better, and here is a specific tutorial on importing custom options. You\’ll be pleased and do spread the word for this developer if you like it (saved me a ton).