I will describe a simple method to share files between your computer and iPad over a Wi-Fi network in Windows 10. You will not need to download additional software or buy any devices. All you need is an ordinary Wi-Fi router.

Step 1. Turn on network discovery and file sharing if you’re not did it already.

If you open File Explorer, go to Network, and see an error message (“Network discovery is turned off….”), you’ll need to turn on Network discovery to see devices on the network that are sharing files. To turn it on, select the Network discovery is turned off banner, then select Turn on network discovery and file sharing.

Step 2. Share a folder on your PC.
Right-click or press a file, select Give access to > Specific people. Choose your Windows 10 account (or any account you prefer).

Step 4. Setup connection on iPad

Open Files app on the iPad, which is a default file browser in iPadOS. Open locations menu > tap on three dots > Connect to Server

In the Server field type your local IP address from Step 3 > Connect > Connect As: Registered User > In the name and password fields enter the account credentials that you gave access in Step 2. For example:
username@outlook.com
password123

If connection is successful you’ll see your shared files right off the bat.
Also you don’t need to enter credentials every time because the successful connection will be saved and pinned in the Locations menu.

Bonus. How do I tell which files or folders I’ve shared over a network?
Just open File Explorer, then type \\localhost into the address bar.