If it is not logical to split it, you should mainly focus on your future use of this table.
Many collumns mean larger rows and therefor less rows on datapages. Such tables could bring several problems.
However you should ask yourself like this (if all or most answers are yes, let it be, if answers are no, split it):
- select statements mainly need all or most collumns
- more then 1 collumn will be very large (text, image, large varchar)
- there will be no same values in many rows in one collumn