ms access courses - Field lookup better way

Lead in---
I have sucessfully made use of suplementary tables to supply lookup to make data entry easier (and of course to secure a limited set of entries in the field in question). However I am finding need for some fields for the data inputer to be able to select from entries already entered in that field whilst also able to enter a new entry. On a form used for the data entry I (thanks to your database intermediate course) was able to enter a combo box (and label) and make it look up values in the very filed and table for which data was being entered and have it update that field. It does what I was looking for except that if there are several entries of the same text/value it lists that value several times. So when the database is bigger it could mean so much scrolling that it is easier to just type it in!

Question---
Surely there is a better perhaps very simple way of achieving same field lookup (similar as works in Excel).