I've developed a "MasterDataFile" that has a lot of company data. The file contains a "MasterData" Excel-table. Only management should be able to see the entire contents of this file.

Based on this file I am building reports for management and individual employees.

Individual employees should be able to see and update their reports, but they should not be able to see the full contents of the MasterDataFile. The individual employees can work at any computer, they don't have personal logins and the company has a server.

Can you give some ideas to what you think would be a good security solution for this?