Why would you want to do this? It is contrary to Relational Database Management System design. Please read this white paper on the fundamentals of an RDMS design.
http://sbuweb.tcu.edu/bjones/20263/Access/AC101_FundamentalsDB_Design.pdf
Why not just use a query to extract the information that you need when it is required. Then the results are dynamic when you require the information instead of static. This is the beauty of using queries. The information is available as needed.
Suggest you read what Allen Browne has to say about this matter.
Microsoft Access tips: Calculated Fields