Could it be a pop-up-menu?
In layout mode, select the field you want to work this way. Then, in Inspector, go to the Data tab and click "control style" and select "pop-up menu". In values from, create a new list and set: use values from field. There, you will use the values from first field, but you can also display values from a second field (from a related table).
Another option you might consider is to "show values only from second field", in the Window "Specify Fields for Value List <name>". It will show just the option the person has to choose in the layout, but the data will be from the first column. Think of it at a field of "select your profession": the person will see the profession, but the field will have the foreign key.
The approach described by H1$c can also be used with the drop down list format. Though it can take a bit more work to get everything to correct display once you select a value and exit the list.
Can you walk me through doing this via the drop down list?
First, you need a relationship linking your table of values to the table specified for your layout that matches by the column 1 values.
LayoutTable::DropDownListField = ValueTable::Column1
Your value list would be set up as H1$c has specified
But then you add the Column2 field from ValueTable to your Layout. You use behavior options in the Inspector's Data tab to clear the "Browse Mode" check box so that this field cannot be entered on your layout. Give it an opaque fill color and place it on top of your drop down list formatted field. When you click on the Column2 field, the drop down list hidden behind it pops to the front and displays values. After you select a value and exit the field, it disappears back behind the Column2 field--which now displays the corresponding Column2 data that you just selected from the value list.