can you watch movies from a hard drive on an ipad

A little hard to advise and help you when you provide NO information about your iPad.

Here are my questions to you.

What year and model iPad do you have/own?

The “A” model number can be found on aluminium back of your iPad in small print right under the larger bold print “iPad”.

What iOS/iPadOS version is this iPad, currently, running?

What is the rated, internal data storage space/capacity of your iPad model and how much of this free, internal data storage capacity is left inside of your iPad model?

All of that additional info can be found in the Settings app, General settings panel, About.

Please attempt to answer all questions asked.

Thank You.

Yes, this is possible on new iPad models running the current iPadOS.

Best of Luck to You!