How to add a drop-down list in Excel? It’s a really simple task.
First of all, we have to have our list (1). Then, we have to select a cell or cells to which we want to add the drop-down list (2). Then, we’re going to the Data tab (3) and click on the Data Validation command (4) (Fig. 1)

In the Data Validation window, we have to select the List option in the Allow bar, then we’re selecting the range and write it into the Source bar. Then OK (Fig. 3)

Now, we have a drop-down list (Fig. 3)

Since our cells with data are in a table, when we add a new line to the table, it also involves the drop-down list.
Even, if we cut and paste our new data, the cells in the selected column will still have the drop-down list. What’s more, in the newest Excel version, we have even Lookup options. We just have to start writing the first letter of a word we’re looking for, then press the Tab key.

This function, however, doesn’t work when we start from the middle of our text. It works only with the first letter.