is there any way to Insert Multiple items into list using nintex form
1. Create a form including a repeating section
2. Add your relevant controls to this repeating section
3. Create your workflow including the query xml action
4. For Each Action to create a single item by each data set of your repeating section
btw. : AS @Marian Hatala said, it is not possible to create multiple items by a single New Item Form without any workflows.