Thank you for the query.
This lumps you have found are most likely lymph
nodes. Such node is a kind of immune system center where the white blood cells are waiting for bacteria. And as the mouth is a first place where the air comes (the air and many many bacteria and viruses), mouth and head area contains many lymph nodes.
It is a very normal thing. Throat area (where you have palpated this small balls) and neck area are typical lymph nodes locations. Healthy lymph node is small, rounded, movable, with smooth surface.
Sometimes lymph node can get enlarged. Usually it happens due to an infection. Sometimes cancer can be a reason of such enlargement indeed. However cancerous lymph node is usually hard, not movable, with rough surface and painless.
If your lymph nodes are bothering you, please visit a doctor for physical examination. In case of enlarge lymph node, ultrasound
can be done.
Hope this will help.