You selected to import as DNG ... this tells LR to create a DNG for every file you selected to import.
If you did not do any work and these are the first imports, I'd suggest to mark all the DNG files and remove them from LR and from the disk (you'll be asked for this). After that you can start from scratch and import the photos again.
It made copies of jpegs and wrote DNGs for each raw file.
There's probably a better way but this tedious process worked for me. Essentially you have to select each date-titled folder that was created, in the Navigator pane. Open, delete all, back out and remove that folder. The folder will still be on disc but empty.
Since there were relatively few DNGs created in the whole process I didn't bother to preserve them, intending to start over.