Default size is configured at 1024000 (1MB) which prevents any notebook bigger than a MB to fail. Zeppelin distribution comes with a file /usr/local/Cellar/apache-zeppelin/0.6.2/libexec/conf/zeppelin-env.sh.template Make a copy of this file and rename it to zeppelin-env.sh increasing the size to something bigger.
$ vim /usr/local/Cellar/apache-zeppelin/0.6.2/libexec/conf/zeppelin-env.sh.template
export ZEPPELIN_WEBSOCKET_MAX_TEXT_MESSAGE_SIZE=10240000
$ zeppelin-daemon.sh restart
https://oleweidner.com/blog/2015/getting-started-with-spark-on-osx/