Add images as folder?

Hi

On Amazon I have a folder with 380 images.
My Amazon Echo and Fire TV devices use the images as ScreenSavers.
Now I have downloaded the 380 images.
Use several tablet on the wall, and wanted to insert them with it.
Now I see that I have to select each image individually ?
With 380 images, this is very time-consuming, and then per tablet ?

bye

Markus