The Google Cloud Datalab team will update this page with solutions based on user experience and requests. See the Support page for additional help.
You can see Cloud Datalab resources in use by clicking on the Running Sessions button in the Datalab menu bar. If you have kernels running for notebooks that you are not using, close them to free up memory and any associated CPU resources. You may also want to try a different machine type to improve performance (see Choosing a VM machine type).