Hi!
Okay, in general this is how you should set up this type of form with tabs. On the form it self (detail section) you will place the company identification information: companyid, companyname are the two most common. The tab control will be in the detail section as well. On the first tab place company demographic information: Address, city , state, zipcode, general phone/FAX numbers, website etc. The contacts should be stored in a separate table which will have the companyid and the contact information (you should probably set up a contactid as an autonumber to keep the number of fields in the primary key down). Then on the Contacts tab of the form place a subform and, going through the wizard choose the contacts table as the source and the companyid to connect it with the main form and datasheet view. When you go from the main form to the sub form, Access should save the record in the main form and you should be able to edit add and delete contacts.
If you can't, let us know but, at that time we will need extensive information about your application to help.
hth
Jeff Bridgham
Purdue University
Graduate School
Data Analyst