Q: When using the Smart Keyboard on a flat surface (like a table), is it normal that the keyboard is lifting off the surface of the table due to the weight of the iPad Pro?

It appears to be an issue with a bad assembly, if you see the ones on internet, all of them have a little gap between the last flap of the keyboard and the followin one, at least on mine that gap os not present, causing the two flaps to overlap, and cause the ipad to have a bump when on a flat surface, this makes the weight of the ipad sufficient to lift the keyboard, and gives and awful feeling when attempting to type on it.

I Use my keyboard on all kinds of surfaces and have not seen this problem unless the surface is not a hard surface (i.e. A desk, table, etc...). To solve the problem I use the box my Apple Smart Keyboard came in with some shelf liner I bought at Lowe's Hadware, the kind that is sticky (although not to the touch of skin) to keep a hard surface under it while folded for use of the keyboard. Now, even if I am laying in bed like I am ATM or in the car, or anywhere, I am able to use my new iPad Pro and it's Smart Keyboard all the time.  Be careful to not buy an off brand accessory, especially when something new comes out to avoid knock-offs problems with design and the end result to the purchaser.