You can use #Column.autocomplete on a text-field column to enable autocomplete behavior for users entering a value.
Use #Column.autocomplete
Add #Column.autocomplete to the column for the text field where you want autocomplete enabled.
For example, use it on a field in which a user enters text and should be able to use autocomplete:
#Column.autocomplete
When the field is shown, autocomplete is turned on for that field.
When to use it
Use #Column.autocomplete for text-entry fields where autocomplete is appropriate.
For example, a user entering a value in a text field can use the field's autocomplete behavior rather than entering the complete value manually.
Related column settings
#Column.autocomplete controls autocomplete behavior. It does not move keyboard focus to a field. To move focus when a field appears, use #Column.autofocus.
Use #Column.Texttype when you need to specify the HTML input type for a column.