Can a field in a table get its value by referencing another table?

[kelly d via AccessMonster.com]

Can a field in one table get its value automatically by referrencing the
value of another field in its record against another table?
as best I could explain it, I'm sure thats about as clear as mud so let me
explain thru example.
I have one table that has all the zipcodes for colorado and their associated
city. I have another table with all the zipcodes that all my various
contractors work and their associated city.
an input error occurs when dealing with the denver metro area cuz most all
the cities that make up the denver metro have an official name as recognized
by the US postal service (which is where my colorado zipcodes table gets its
info) and an informal community name which most people refer to that city by.
(I.E. one cities official name is Littleton but half of littleton is referred
to as Highlands Ranch) so in inputing the zips and cities that contractors
work as listed on their contracts, some contractors that work Littleton
listed their zipcodes as Littleton while other contractors list the same
zipcodes as Highlands Ranch (and I'm sure thats happened a million more times
thru out the other cities of the denver metro that I havnt found yet) which
is causing some of my queries that are city-dependent not to consolodate. So
is there a way for my contractors zipcode table's city field to get its value
by referencing that records zip with the corresponding zip in the colorado
zipcodes table and returning the city associated with that zip into the city
field of the contractors zip table?
This sort of thing is a cake-walk in forms and reports but I just cant seem
to think of how to do it in a table.
Thanks for any help
Kelly D

 

[kelly d via AccessMonster.com]

I created a query with the contractors zip table and the colorado zip table
inner joined and in the query gets all the fields from contractor zips except
city which it gets from colorado zips and I've made my forms by based on the
query rather than the table. Is that the way to do it or is there a better
way?

P.S. now that my forms are based on the query rather than the table, they
seem to load and run slower. Is this usually the case when recordsources are
based on queries rather than tables cuz with the network connection this app
has to the back-end on our corporate shared drive, it's already running slow
enough, I dont particularly want it running any slower.

Thanks
Kelly D