Q: Photos

There are several ways:

• Sync the photos to your iPad using iTunes, see:  Sync photos to your iPhone, iPad, and iPod touch in iTunes - Apple Support
• You can also transfer the photos from iPhoto using My Photo Stream or Shared albums:  iCloud: iCloud Photo Sharing FAQ or  iCloud: Photo Stream FAQ

Many different ways depending on what you want

iCloud Photo Library

iTunes Sync

MyPhotoStream

iCloud Photo Sharing (shared PhotoStreams)

LN

iCloud Photo Library will not work with iPhoto, or do you think, the title of the question means that Ralf is using the Photos for Mac app?

Since OP does not give us any information about what system they have no one knows - being in the iPhoto for Mac forum gives it  about a 50% chance of being about either program - basically with no information one guess is as good an another so that covers both iPhoto and Photos possibilities

LN