Is it possible

Not enough information. Use it how?

well you can remote desktop to the mac mini which is a computer

then the mac mini would be doing the work just sending the visual across to be displayed on the screen of the ipad

Rudegar's option is about the only way you can use them together.

But otherwise, no. Your iPad uses a completely different CPU and OS. It will only run as fast as the hardware you have. As with any computer of any brand, older will be slower.

Also, an iPad is not in any way a laptop. It's a completely different kind of device with a locked down OS you cannot directly access. It can only run apps written for iOS. And up until iOS 13, you couldn't even use a mouse with one, though that still isn't easy.