If you decide you want to switch to work with a different dataset, click the Datasets link in the top left:
|From version 9.9.1 onwards, the dataset name at the top of the screen is a clickable link that you can also use to return to the dataset's info page on the catalogue screen. In addition, if you opened a saved table, the table name will be displayed in the top bar too; this is also a link back to the catalogue.|
Switching to another dataset or table will clear the current table. If you think you might want to use the table you were working with again, you may wish to consider using the save table feature.