By using fields, you don't need to maintain email signatures for each employee. Instead, you maintain only a few templates.
You create an email signature template by inserting the fields:
Your template will pull and merge details found for each employee:
How to insert fields
Watch how to use the preview to see how employee data is merged.
If you have different company names and locations, then the information is effectively maintained for each employee in the Employees menu:
If all employees are working in the same company and location, then you can remove the fields and update directly in the template: