The following code will list all the datasets in the project and all the tables under the datasets in the project. Call this method in the main method and see lists of tables under each dataset:
Do not start your dataset name with an underscore (_) because this convention is used by Google to hide datasets. Hidden datasets contains temp tables generated by the query output.
If the project has a huge number of datasets, then use labels for them; this will make searching for datasets easy via API. Use the ListDatasetsOptions.Filter property to filter datasets by label. To retrieve datasets via pagination, use the ListDatasetsOptions.PageSize property to set the page size.