Write a blank line to CSV

Greetings and happy new year!

I'm attempting to write a series of tables to a CSV file, and would like to
insert a blank line after each table. To do this, I use:

write.csv(NULL,"tables.csv",append=T)

which appears to work, except that this warning is thrown:

Warning message:
In write.table(NULL, "tables.csv", append = T, col.names = NA, ?:
appending column names to file

I tried col.names=F in the write.csv call, but the argument is ignored,
presumably because NULL does not have col.names.

Is there a better way to insert the blank lines? ?Many thanks for
enlightening me!

--Krishna