So why do you need the field names? Also, somewhere the table structure must be being defined, so at some point the actual fields names are known. For example, one solution may be to pass the field names as well as the data in the tables.
How is that you have the data types? Where are these coming from?
I'm honestly trying to help, but really you're not giving enough information. I've been handling dynamic tables for years and have never had a problem with them I couldn't solve.