Can I transfer photos from my iPhone 7 plus to my iPad Pro using an Apple lightening to c connector?

No. Aren't you using iCloud Sync for photos? If your iPad Pro and your iPhone 7 are signed in with the same Apple ID, all you have to do us turn on Photos in the cloud and they will download to your iPad.

On iPhone, go to Settings > Your Name, iCloud, Apple ID, iTunes & App Store > iCloud > Photos make sure it is turned on.

Then make sure on the iPad Photos is turned on in the same way.