You can use batch API to create up to 20 records at once. You can perform these actions on any editable system object. This will help you expedite your work using the API. Before performing batch API actions, ensure you'd like to perform the selected action on all of the selected records.
Please Note
You can create up to 20 records at once using batch API. Additionally, batch API is not available in all licenses, so be sure you have access before beginning the process.