How make a compressed tar when there are too many filenames for the shell to expand on a single line?

As a robust solution, use find to separate filenames by a null character, and then pipe directly to tar, which reads null-delimited input:

find . -maxdepth 1 -name '*.csv' -print0 |
tar -czf archive.tgz --null -T -

This will now handle all file names correctly and is not limited by the number of files either.

_{Using ls to generate a list of filenames to be parsed by another program is a common antipattern that should be avoided whenever possible. find can generate null-delimited output (-print0) that most utilities can read or parse further. Since the null character is the only character that cannot appear in a filename (and the /, obviously), you'll always be safe with that.}

No, you cannot append to a compressed tar file without uncompressing it first.

However, tar can accept its list of files to process from a file, so you can just do:

ls *.csv > temp.txt
tar -zcf ball.tgz -T temp.txt

@slhck points out that the above solution will not work if there are spaces (and probably other annoying characters) in your filenames. This version encloses each filename in double quotes:

ls *.csv | sed -e 's/^\(.*\)$/"\1"/' > temp.txt
tar -zcf ball.tgz -T temp.txt

(This will of course break if you have double quotes in your filenames, in which case you get what you deserve. :)