Is it okay to whack a bible/ganglion cyst with a book?

No. The ganglion is a cystic selling from the joint capsule. Drainage and or cortisone shot will give you temporary relief. If it is painful or very noticeable the only method to definitively del a with a ganglion is surgery, done in an outpatient facility by an orthopedic, or hand surgeon. There is a small recurrence rate of about 10-15 per cent .
Old wives tale. The name "bible cyst" is thought to come from an old practice where you wacked the thing with a big book to get rid of it. The bible was the bigest book many owned back in the day. I've read no descriptions where it worked & see the potential for you to do some damage to the nerve. Remember, george washington died while they bled him for a sore throat. Old style rxs were replaced for many reasons.
I would not try. Although, i hear it all the time from my patients and i believe it worked back when medicine was fairly primitive, i would not recommend it today, as whacking it with a bible may cause injury that you will have to deal with later. Those can be drained and injected with a steroid that may cause them not to come back. Just see your doc!
Question is WHY. Hitting a ganglion with a book is the "old wives' tale". It doesn't really do anything. Whack away! really, draining the cyst and injecting cortisone can help relieve pain. Keep in mind the cyst is still there, just deflated. So will likely come back. If you want it actually gone, have surgery to remove it.
Ganglion treatment. Options to treat or not treat a ganglion are simple. Let me know more about it.
Ganglion cyst. YES. It may break the cyst and cure your problem but then there is at least 50 % chance it will return. This is an old idea. Most Docs would rather drain the cyst with a needle and if the cyst returns remove it by surgery. This method will guarantee the cyst drains but certainly if it returns you still need the surgery.
Hard blows not good. Only if you don't mind a trip to the emergency room to make sure you didn't break a bone. The impact required to break that open is going to have to hurt. It doesn't seem like a good idea to me. The best thing is to take anti-inflammatories like a leave twice-daily and then see your doctor and perhaps have it injected with a steroid after removing the fluid.