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/1.73 m\^2 (Cockcroft-Gault formula) for patients with creatinine levels above institutional normal * Patients with abnormal hepatic function will be eligible and will be grouped according to criteria; patients with active hemolysis should be excluded; no distinction should be made between liver dysfunction due to metastases and liver dysfunction due to other causes; this data will be captured in the case report form (CRF); registration laboratory investigations will be used to assign a patient to a hepatic function group; hepatic function tests should be repeated within 24 hours prior to starting initial therapy and may result in patients' group assignment being altered if different to registration test results * For women of childbearing potential: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive methods that result in a failure rate of \< 1% per year during the treatment period and for 30 days after tazemetostat discontinuation * A woman is considered to be of childbearing potential if she is postmenarchal, has not reached a postmenopausal state (\>= 12 continuous months of amenorrhea with no identified cause other than menopause), and has not undergone surgical sterilization (removal of ovaries and/or uterus) * Examples of contraceptive methods with a failure rate of \< 1% per year include bilateral tubal ligation, male sterilization, established, proper use of hormonal contraceptives that inhibit ovulation, hormone-releasing intrauterine devices, and copper intrauterine devices * Female subjects who use hormonal contraceptives should use an additional barrier method of birth control while on study treatment and for 30 days after discontinuation of study treatment * The reliability of sexual abstinence should be evaluated in relation to the duration of the clinical study and the preferred and usual lifestyle of the patient; periodic abstinence (e.g., calendar, ovulation, symptothermal, or postovulation methods) and withdrawal are not acceptable methods of contraception * For men: agreement to remain abstinent (refrain from heterosexual intercourse) or use contraceptive measures and agreement to refrain from donating sperm, as defined below: * With female partners of childbearing potential or pregnant female partners, men must remain abstinent or use a condom during the treatment period and for at least 4 months after the last dose of study drug; men must refrain from donating sperm during this same period; in addition, female partners of male subjects should adhere to the following: * Intrauterine device (IUD)(must provide medical documentation of IUD) * Hormonal contraceptive (partner must be on a stable dose of the same hormonal contraceptive product for at least 4 weeks before receiving study drug) AND a condom (hormonal contraceptives must be supplemented with condoms) * The reliability of sexual abstinence should be evaluated in relation to the duration of the clinical study and the preferred and usual lifestyle of the patient; periodic abstinence and withdrawal are not acceptable methods of contraception * Females of childbearing potential must have a negative serum pregnancy test at screening * Ability to understand and the willingness to sign a written informed consent document * Has a QT interval corrected by Fridericia's formula (QTcF) =\< 450 msec * Whenever available, archival tissue (block or minimum 10 slides) is requested for molecular characterization, e.g. detection of somatic mutations and/or candidate biomarkers of response; this is not mandatory and lack of available tissue would not be an