import re


data = [['company1', '<U+042E><U+043F><U+0438><U+0442><U+0435><U+0440>'], ['company2', 
 '<c1>lom<e9>kszer Kft.'], ['company3', 'Ernst and young'],
   ['company4', '<c5>bo Akademi']]

for index in range(len(data)):
    data[index][1] = re.sub(
        r'<(?:U\+)?((?<=\+)[0-9a-fA-F]{4}|(?<=<)[0-9a-fA-F]{2})>', 
        lambda x: chr(int(x.group(1), 16)),
        data[index][1])

print(data)