Tazemetostat in Treating Patients With Metastatic or Unresectable Solid Tumors or B-Cell Lymphomas With Liver Dysfunction

Inclusion Criteria: * Patients must have histologically and/or cytologically confirmed solid tumors or B cell lymphoma that are metastatic or unresectable and for which standard treatment options do not exist; patients with hepatocellular carcinoma are eligible without pathological diagnosis if diagnosed on the basis of blood work and imaging * Patients with evaluable disease will be eligible * All patients must have completed any prior chemotherapy, targeted therapy and major surgery, \>= 28 days before study entry; for daily or weekly chemotherapy without the potential for delayed toxicity, a washout period of 14 days may be acceptable, and questions related to this can be discussed with study principal investigator * Eastern Cooperative Oncology Group (ECOG) performance status =\< 2 (Karnofsky \>= 60%) * Life expectancy of greater than 3 months * Able to swallow and retain orally-administered medication and does not have any clinically significant gastrointestinal abnormalities that may alter absorption such as malabsorption syndrome or major resection of the stomach or bowels * All prior treatment-related toxicities must be Common Terminology Criteria for Adverse Events (CTCAE) version 5.0 grade =\< 1 (except alopecia) at the time of enrollment * Leukocytes \>= 3,000/mcL * Absolute neutrophil count \>= 1,500/mcL * Platelets \>= 100,000/mcL * Hemoglobin \>= 90 g/L (9.0 g/dL) * Creatinine within normal institutional limits OR calculated creatinine clearance \>= 60 mL/min/1…