Yes. This functionality is ideal for users who are testing devices and don't want to accidentally consume large amounts of data.
You can pause SIMs from within the dashboard. Click on the device you want to pause and you will see a “Pause Data” button on the top right corner in the “Status Information” header. This stops the SIM from sending and receiving data, but it can be reactivated in the future.
Note that you will still get charged a monthly active device charge for each SIM to maintain the option of reactivating them.