You can use Neo4j's Batch Inserter API to efficiently create nodes and relationships from CSV data, even with large datasets. The process involves creating a batch-inserter instance, reading the CSV file, and using it to create nodes and relationships according to specific requirements such as not indexing properties that are only needed for connecting data, creating schema indexes, skipping certain columns, renaming properties, and converting column values into Neo4j types. To ensure efficient processing, it's essential to shut down the batch-inserter instance at the end of the process. The example code demonstrates how to use the Batch Inserter API with Groovy, handling cases where authors need to be created only once, even if they appear on multiple lines in the CSV data.