ARROW-12206: [Python][Docs] Fix Table docstrings
ARROW-12206: [Python][Docs] Fix Table docstrings

Fix Table docstrings.

Closes #9888 from albertvillanova/fix-table-docstrings

Authored-by: Albert Villanova del Moral <84edf8ee14deef0dafbfab92aa99f85516fea9b8@users.noreply.github.com>
Signed-off-by: Joris Van den Bossche <36c737f86d71d8ee1ddeb1e5c83102ee5de8f97c@gmail.com>

apache/arrow,icexelloss/arrow,laurentgo/arrow,laurentgo/arrow,cpcloud/arrow,cpcloud/arrow,apache/arrow,apache/arrow,apache/arrow,wesm/arrow,apache/arrow,wesm/arrow,wesm/arrow,cpcloud/arrow,icexelloss/arrow,kou/arrow,cpcloud/arrow,cpcloud/arrow,cpcloud/arrow,icexelloss/arrow,icexelloss/arrow,icexelloss/arrow,laurentgo/arrow,cpcloud/arrow,icexelloss/arrow,icexelloss/arrow,wesm/arrow,apache/arrow,kou/arrow,icexelloss/arrow,apache/arrow,kou/arrow,cpcloud/arrow,laurentgo/arrow,laurentgo/arrow,wesm/arrow,apache/arrow,kou/arrow,wesm/arrow,wesm/arrow,kou/arrow,apache/arrow,cpcloud/arrow,apache/arrow,wesm/arrow,wesm/arrow,laurentgo/arrow,apache/arrow,laurentgo/arrow,icexelloss/arrow,laurentgo/arrow,icexelloss/arrow,cpcloud/arrow,apache/arrow,cpcloud/arrow,kou/arrow,icexelloss/arrow,cpcloud/arrow,cpcloud/arrow,wesm/arrow,icexelloss/arrow,kou/arrow,wesm/arrow,kou/arrow,kou/arrow,laurentgo/arrow,cpcloud/arrow,wesm/arrow,laurentgo/arrow,wesm/arrow,wesm/arrow,laurentgo/arrow,laurentgo/arrow,laurentgo/arrow,apache/arrow,kou/arrow,laurentgo/arrow,kou/arrow,kou/arrow,laurentgo/arrow,apache/arrow,kou/arrow,icexelloss/arrow,icexelloss/arrow,kou/arrow