def get_unique_tables(data):
    """Returns unique tables in data using 'Table Name' column in header row"""
    hdrs = data[0]
    tbl_idx = None
    for idx, hdr in enumerate(hdrs):
        if hdr == "Table Name":
            tbl_idx = idx
            break
    assert tbl_idx is not None
    return set([c[tbl_idx] for c in [row for row in data[1:]]])