How To Pass Data From One Table To The Next?

Hi everyone! :)

First off I have to say I'm not an Access Guru by any means. I can make a very very basic database in access but beyond that I'm toast.

So I've just started working on a project that is in it's second year. The project was started last year by a student and she created, what seems to me, to be an adequate small database for the project. I've noticed however that when entering data, some of it has to be entered twice. This has been made easier through the use of the look up tab in the field definition (?). However, I worked with a student before who created a database where the primary key value of a "parent?" table was automatically forwarded to the corresponding field in the "child?" table.

So here's a hypothetical, let's say you have a restaurant, and one restaurant can have ummmm many tables, and then one table can have manyyyy chairs! There's a unique restaurant id created in the restaurant table, which is say needed with a table number to create a unique table id in the table table, which is in turn needed with a chair number to create a unique chair id in the chair table? So you basically have 3 tables where unique ids are being created. So then lets say you have a chair description table that has fields in it to contain all the ids made previously, as well as some of the information entered to create the unique fields (i.e. table number, chair number). My question is..if I've already entered this data in previous parent tables then why is it that the data doesn't carry forward to these fields? Is it because these fields are not primary key fields in this last table? If that's the case then is there a way to set this up? Right now there's a select statement used in the look up reference option that has something to the effect "select table.table_name from table;". So I know what it's doing and when I enter data I can select the table id I need. It just seems a bit redundant data entry wise to enter yet again values I entered the table before, or values that were generated for me in the table before.

Is there a way to have these fields automatically populate with the corresponding data that was entered to get to this table? Does it involve modifying the select statement to involve a where clause (terminology? clause?). Any ideas would be very much appreciated! Thanks.

Sue