Currently I think there is no way to specify custom column names for CSV files. It's possible to specify the full schema of the file, but not just column names.
See the related discussion here:
The goal of this is to re-use the CSV type-inference but still allow people to specify custom names for the columns. As far as I know, there is currently no way to set column names post-hoc, so we should provide a way to specify them before reading the file.
Related to this, ParseOptions(header_rows=0) is not currently implemented.
Is there any current way to do this or does this need to be implmented?