We will be carrying lunch boxes in bags & would like to know, if that would be allowed during security check at skydeck. Is there a locker or something to leave/store our bags at skydeck before the security check to avoid delays/hassles?

You can carry food. But no place to sit n eat.

I think you can take it in, but there is no place to sit and eat. People were sitting on the ground as there are no chairs or benches as such to sit down on. Also, depending on what time you go, the whole attraction might take 1 hour or so for sightseeing. Not much to do up there, except enjoy the view. Maybe that's why we didn't see many people munching anything there because they weren't there for very long.

No lockers. All bags go through security x-ray machine. All people walk through the metal detector also. So if you are carrying bags they will be with you for the duration of your visit.

I believe you can take that in

No there is no lockers