Firstly let me start by saying that I am a relative beginner to access
database development and a raw beginner to any programming. What I am trying
to do is to work out a way to store multiple data within one field. I know
that the theory is one field equals one entry and a field that requires more
than one entry should have its own table, however I don’t know how to get
this to work with the application I am looking for in my database.

Detail on my database.
This database is to store costing information on the valuation of assets.
There is a transaction table “Assets” and a number of other tables “generic
asset name”, “Manufacturer”, “Industry Classification” and “Client”, (If you
need to know the more relationship information let me know). In this
transaction table there is all the detail pertaining to the specific asset,
descriptions, model number, specifications, and more importantly the costing
information and a date this costing data was gathered.

My problem begins when I wish to revalue/update the asset; I will lose the
original data. Ideally what I would like to do is to store the historical
cost data in order to be able to develop graphs and future projections.

However there must be a better way than to just have lots and lots of date
and costing fields in the transaction table.

If someone could please help me it would be greatly appreciated.