hides it down the side of her high chair.
I think this is quite common, mine did it too and I've read other LOs sneak stuff down the high chair onto the seat. We used to joke that he was saving stuff for Ron - lateR on - yeah bad joke but it was almost as though there was a built in survival guide to save food for later, I found it quite amusing. Maybe the bad joke helped. When mine looked like he was finished and we were tidying up I'd ask him if he'd saved any for Ron and he'd look around his seat, find the bits and pick them up, either eat them or pop them on the plate for clean up.
I'm a BIG believer in family meals even if Mummy (CM etc) only eats a small snack at the same time. If there is less food eaten at family meals it could be down to enjoying the social aspect and once that is the norm the eating part will take off. LOs look to us to model all sorts of behaviour from what is safe to eat to keeping it on the plate/table to using cutlery. I honestly don't think they can be expected to learn any of these unless they are (mostly) eating with someone.
Many years back (long before I had DS) I saw constant food battles between a friend of mine and her son, he was about 5 at the time. He would ask for food, she'd cook it, give it to him but not eat with him, he wouldn't touch the food, she'd tell him to eat it, he'd say he wasn't hungry, she'd shout, he'd cry, she'd take it away (and eat it herself - IMO showing that really she could have sat down and shared the meal). Then it would be time to go out, he'd delay by saying he was hungry, she'd cook it, give it, he'd ignore it...more crying, she'd take it away and eat it...they'd go out, he'd ask to go the bakery for a sausage roll, she'd shout at him because he'd been given 2 or 3 meals already which he never ate, then she'd give in buy him one, he wouldn't eat it...
argh, I just thought if only she could see what I was seeing. He just wanted her attention. I minded him a few days whilst she was at work, I made us a meal, ate with him, he ate the lot without a peep of complaint. Now I'm not saying this is what is happening with your DD, there is a big age difference for a start, but it really taught me how important eating habits are and how the battle can get out of hand for what really ought to be a time of bonding, communication and enjoyment.
I also think if she is ever going to join family meals she needs to be introduced to those flavours (even if less spicy for example) that are regularly eaten at home otherwise when she is older she will still be requiring a separate meal to be cooked and not joining in with whatever you have made for you and DH. I DO make changes and allowances in my cooking and what I give to DS but it is always based on our regular meal (here things like making a milder curry then adding more spice to mine and DP's after DS's is served if we really need it hotter, or serving DS boiled potato rather than mash which he doesn't like, he gets a tiny portion of mash so that one day he will try it).