It possible to upload a pre defined list of keywords. The authors of the abstracts can choose their keywords from a pull down menu.
First you have to change the setting in the abstact module.
Go to the Abstract dashboard and choose the module settings via the gear icon.
In the new screen check the box at 'Advanced kewyword field configuration'.
Add the keywords you want to use via the Module content -> Kewywords tab.
Change the setting of the keywords to a pulldown.
Page editor -> Abstract wizzard -> abstract data -> right mous button on the keyword field -> field properties -> choose 'Pulldown field'.