Currently there isn't an easy way to achieve the described scenario with RadAutoComplete component. We have this logged in out Feedback Portal and you could follow and vote for the item on the following link: Autocomplete: Show all suggestions immediately when focus on the input field
. We are working on improving the control functionality and I hope we will have this feature with the upcoming R3 Release (scheduled for mid-September).
Hope the provided information was helpful.
Do you want to have your say when we set our development plans?
Do you want to know when a feature you care about is added or when a bug fixed?
Telerik Feedback Portal
and vote to affect the priority of the items