It needs to be taken in the context of the full blood and clinical picture. I recommend a professional evaluation.

Need to look at the whole CBC and smear to evaluate.

Monoclonal B lymphocytosis (MBL) is defined as the presence of a clonal B-cell population in the peripheral blood with fewer than 5 × 109/L B-cells and no other signs of a lymphoproliferative disorder. If reactive and polyclonal, then viral is usually the cause such as hepatitis, HIV, autoimmune, smoking, hypersensitivity, acute stress, lack of spleen.

Need to get to your doctor ask to get Flow cytometry test. If monoclonal, then need bone marrow biopsy.