Can I control an iPad with an Apple TV remote?
There's no way to use the remote which comes with an Apple TV to control the iPad, but you can connect an Apple or third-party bluetooth keyboard to control your iPad.
Quoth Apple:

Apple Wireless Keyboard and Magic Keyboard compatibility with iOS devices
Apple Wireless Keyboard, Magic Keyboard, and many Bluetooth keyboards that use the Apple keyboard layout work with these iOS devices.
https://support.apple.com/en-us/HT202041
Note: In addition to Apple keyboards, many third-party Bluetooth keyboards that use the Apple keyboard layout work with iOS devices. Check with the keyboard manufacturer for additional information.

After connecting a Bluetooth keyboard, Mac-like keyboard shortcuts will work to control video playback on the iPad. Spacebar to play/pause, arrow keys to skip forward and backward and to control the volume.