Title explains it. Test case:

~~~

.. csv-table:: foobar
    :quote: ÷

    irrelevant

~~~

the bug is in parsers/rst/directives/tables.py, line 177:

self.quotechar = str(options['quote'])

when using python2, this causes python to try and decode it with the ASCII codec, which fails.

if anyone tries to fix this, please look for similar instances to fix.