I have a Form used to select multiple products in a category.  In the form I would like to select a Category from a List Box or Combo Box and then select for the next field in the record a product from a list of products in that category. It is not feasible to use multiple Queries as they are too many Categories and each category has many products.  
Should I have a table with field 1 the Category and the Next Field the Products,  But not sure that is correct and it would use a lot a data and hard to update.