These are called drop down lists and there's a similar format called a pop up menu. There are a number of options you can specify both for the value list that provides the list of values and the also appearance and function of the drop down or pop up for a field where you've specified this format.
Let's say you want a list of five names: Apple, Orange, Cherry, Kiwi, Mango
Open Manage | value lists and click new.
Type in a name for your value list and enter the above list in the custom values box. Press return after each name.
Click OK to dismiss the dialog boxes.
Enter layout mode and place a text field on your layout or select one already on it.
In the inspector select either drop down list or pop up menu in place of the default "edit box" setting.
In the "values from" drop down in the inspector select the name of your custom value list.
With a drop down list, you can select other options if appropriate such as adding the Arrow feature or enabling auto-complete so that you can type in a few letters and the first value list matching what you have typed "completes" the selection for you.
Now return to browse mode, saving your layout changes and try out the drop down list, You may want to experiment a bit with both the drop down list and pop up menu options to see how they differ.
This is just the simplest possible value list. More sophisticated value lists that list two columns of values, are drawn from values entered in a table (instead of the custom values box), or which list only a subset of the entire list based on a value selected in another field (called a condiatonal value list) are all possible. The same value list can also be used to produce radio buttons or check box groups.