It is relatively simple to add a list of possible values to an Editable table. Go to the Configure Columns step, select the Column Name. In my example below it is DEPT_CODE. In the Possible Values attribute, type a formula similar to the one I have in my dept mapping table. After the percent sign, you provide your table name, then a forward slash and the columns selector formula. "!LIMIT_COLUMNS" is a formula which defines the columns you want displayed when a user selects the column. Then comes an open bracket, the name of the field in the table you referenced, and then a closing bracket. Save and check-in your changes when finished.
%<Table Name> / <columns to display>
%HIG Cost Centers/!LIMIT_COLUMNS[Department Code]
Then when the user creates a new row, or modify an existing row, they can type the code into the column, wait to see if the value exists: it will be displayed so they can select it. Or click the Find to filter for the department.
**Be cautious before apply this formula to an existing editable table that already has data. If a value is not in the list you configured, they will get flagged in red with an error message stating "Entry not listed in possible values". This obviously helps identify where a department value possibly needs to be corrected. However, if there are any red highlighted cells in the report window, you will not be able to make a change to a different department unless you filter out the error value(s), or filter for the specific department. Once the window shows no red, the Save button will be enabled.