As a matter of principle you should not delete any MSF010 table codes, as long as there are any other records in the system (eg work orders), that point to them. Or your system will become more or less inconsistent. On the least severe scale, you won't be able to review the MT code's Description, when you review work order online or in reports. At the other end, the system will malfunction if the codes play a role in system logic: noting that there are Associated Values defined for the MT code, which indicates that they are not simply used for Descriptive purpose, but could drive some functionality in the system.
If codes are no longer required, an alternative would be to alter the Descriptions and insert 'DO NOT USE', leaving the old description also in place. That would allow to review history of work orders, as well as stop users from using these codes in the future.
The cross reference records may serve various purposes and it is even riskier to delete. The only safe approach is to use a system archiving facility if one were available for work orders, in order to remove older work orders/ cross references, then check if any work order still exist with the MT codes, and if not, then manually delete the MT codes (as an archiving routine would not delete MSF010)