Hello Good After Noon,
This might be seems a fracture
of your little finger and first metacarpal bone.
According to your history you slammed your right hand down on a table, so there was a strong voluntary force applied, which stroked on very hard surface of the table.
So there can be a fracture along with tendon injury
and edema, which is causing pain, tenderness and swelling at that site.
Fracture needs to be managed by immobilization, like with a POP slab, and if there is any displaced fracture, then surgery may be needed.
So now simple steps to be taken:
Just go for a x-ray right hand and wrist, nothing serous injury is looking for the arm.
Go to orthopedic doctor for further management.
Dr. Naresh Jain.