Hi.. Thanks for the query.. A sore non movable bump at the back right side of palate if it is bony hard can be due to bony torus formation that is overgrowth of the bone.. The mucosa over it gets irritated and it is the cause of pain.. The other causes can be abscess formation.. So first of all consult an Oral Physician and get evaluated so that he can rule out the exact cause of the lump and if there is a doubt an x ray can be done for confirmation.. For now you can apply Lidocaine gel over the lump to reduce pain and along with it you can also take pain relievers to relieve pain.. Take soft and non irritant foods .. Do warm saline gargles.. Hope this helps.. Regards..