We can add the drop-down list in excel files. The given below steps and video might help you.
Step2. Type items for display in drop-down.
Step3. Select area where u want to display drop-down.
Step4. Go to the data tab.
Step5. Select the data validation tab and click on it.
Step6. Select the setting tab in data validation.
Step7. Allow the list validation criteria.
Step8. Add the source of typed items Step1.