The events were slightly clearer in the film's original screenplay. In short, she's entering all of the advanced scientific information she's gathered:
Lucy is engrossed in the thousands of items of coded information scrolling past her eyes. It's illegible [sic] for any normal human being.
FLIGHT ATTENDANT: Miss?
LUCY: (riveted to the screen): You should wipe your nose.
The Flight Attendant doesn't understand.
A drop of blood appears in one nostril.
The woman touches her nose and realizes she's bleeding.
Slightly flustered, she scurries away. Lucy keeps working.
Up ahead, in the galley, the Flight Attendant talks animatedly to her co-workers. Points toward Lucy. The CABIN MANAGER decides to take matters in hand and comes over.
CABIN MANAGER: (politely) Miss, you really need to shut down your computers now.
Lucy puts her finger to her mouth, hushing him.
On her screens, Lucy finally reaches the end of the coded signs, gives a little satisfied sigh and gently closes both laptops.
LUCY (big smile): Twenty-five centuries of knowledge in eleven hours. I couldn't go any faster.