I have a small hard lump in the palm of my left hand 1 centimeter across located two centimeters directly below the base of my ring finger. Any ideas?

PALM LUMP. It might be an inherited disorder named dupuytren's contracture. This is a painless thickening & contracture of tissue beneath the skin on the palm & the fingers. Also known as the "viking" disease as it often occurs in people of scandinavian or northern european ancestry. Surgical procedures often work.
Dupuytren's contract. Likely a dupuytren's contracture: sometimes inherited, sometimes seen in alcohol excess, sometimes other causes. Can cause (usually)painless nodule; can lead to shortening of the extension of the finger. New treatment available; also anti inflammatory injection rx and surgery, if needed.
Benign tumor. It can be many things such as a benign giant cell tumor of the tendon or even a mucinous psuedocyst. Both can be treated by a hand surgeon.
Could be. Dupuytrens contracture causes nodules to form along the flexor tendons in the palm. Eventually this may cause pain with full extension of the finger or limit range of motion. In the early stages is not painful, red or responsive to "arthritis" medications. It would be unusual to have a bone spur in this area, but get it checked by a doctor if it bothers you.