Uploading to table ec_product

In this project I had to stretch ec_products and now I have to load it for the first time.
2000 records of -+ 90 rows.
I realized that nid relates to the node table (which autoincrements) but the vid I have no idea where it might come from. In spite of being perfectly synchronized with the nid.
So, how do I load 2000 records and keep nid synchro with node.nid and vid synchro to whatever?

Thanks