What about using a storage bench as seating along one of the sides of the dining table instead of chairs so that the kids can store some of their crafts/toys?

Without seeing a floor plan, its really tricky to know what to suggest! You could always get a gate-leg table that folds away when not in use for dining (which would maximize play space). Or get a rectangular table that sits lengthwise along one wall to leave more floor space for playing on the other side of the room.

so this is my dining room - as for floor plans, it's basically a square (but with one side a little longer). that photo is taken over the half door, and there are windows on two walls. it's pretty small, especially with a table and chairs in there. a storage bench as one seating option is a great idea!

I'd choose a very small dinning table that seats four only and replace the high chairs with trip traps. (Maybe even use a card table). Because the trip trip allows a lot of personal independence, it can double as a play table. Get rid of yours if you have one. If you choose a card table, you can also make or buy one of those little fabric card table play houses. Eating + crafts + play house all in one.

Choose a single flooring type or rug to unify the different elements of the room.

I'd run Ikea Billy bookcases on one wall and add doors (the kind you can decorate) to some of the bookcases. They make *great* toy storage, allow you to keep everything organized, and help the toddlers learn how to put away their toys. Choose at least one half size unit for books because trust me, books are like rabbits. Get rid of your (cute) book storage because it is too ineffecient.

Plus, forgot the obvious, you can shut the doors and it is a more peaceful space.

I was going to suggest the same -- either a table that folds away or a table against the wall. To save space, we have a bench against the wall and we push the table against the wall when not in use (the bench tucks under the table). If you can find a bench with storage for toys, that would be great too!

For decoration, you might paint a blackboard space on the wall and put a frame around it, allowing your children's changing artwork be the focus. Or, hang a variety of frames on the wall and mount clips inside them so you can change out art work on paper quickly.

Instead of using a sideboard to store china and linens, use it to store toys. Or, use a low bookshelf with baskets for toys instead. Mount floating shelves on the wall for storing china and glassware, out of reach of the small hands.

Our dining room doubles as our play room, so I'll tell you what we did. The dining room is the center of our house, has no closing doors and can be seen from every room on the 1st floor, and is where we eat most meals. So, we needed play solutions that look decent. We have a nice storage bench with baskets under one window to organize most of our toys and books. We also have a nice wicker hamper type thing to organize larger things like dress-up costumes. Both of these blend into the decor pretty seamlessly. We have additional toy storage in one side of our buffet, and we store all our kid art supplies, puzzles, and educational things behind closed doors/drawers in the bottom of our china cabinet. Anything that can't fit in these areas live up in the kids' rooms (especially their many books--we just keep a rotating small collection in the dining room). The only exception are small indoor bikes, pushing toys, etc.--we committed to only getting attractive things that we don't mind looking at in our dining room, and they mostly live in the corner when they're not being used, or in the foyer/basement if we're entertaining. I think a gateleg or other expandable table is a good idea if you can. We just have a standard big table that comfortably seats four or squeezes 6, and it is fine--it is sturdy, and is our main everyday eating table, as well as art table, and often our work/study table, as well, so there was no way we were going to sacrifice that size and put a tiny table in there.

What about something like this - http://www.ohdeedoh.com/ohdeedoh/tables/hot-or-not-daily-shelter-106292 but made with rolling blinds hung on the underside of a regular table with a nice lip on the edge (skip the roof found in this link). The storage bench sounds awesome. We have leather parsons chairs at our table and I love them for both the look and the durable/wipeability with kids. All options would allow the room to look like an adult dining space when you want it but have a fun kids play area as well.

Oh, and we also have a mantel in the dining room with a blank wall where the fireplace used to be (it was closed up), and I painted that area with black chalkboard paint and magnetic paint. So, it's a fun play area, but can also be cleaned up and mimic a well-used hearth quite nicely.

Our dining room is our playroom right now and while I am anxious to move it back to dining status (it's in the center of our house with no closing doors either), we are leaving it as a playroom until the kids can be less supervised. Right now it really works because the kids are nearby when I'm making dinner, washing dishes or checking email. It also works great when we have friends with kids over because the kids are nearby and all in one area. For now, we have a small table in our kitchen. Some day we'll move all the toys up to the kids' bedrooms and use the dining room for dining, arts and crafts, puzzles and games.

i think a fold away table would work nice. then use a couple of chairs. my aunt made the formal dinning into a play room they only used the breakfast space for dinning. if you have a breafast area i suggest doing the same. that way little bits of food that might fall and go unseen wont become choaking hazards while the kids have play time.

You could get a regular table and chairs with the highchairs that fit onto the normal chairs instead of having separate high chairs.

If you make the dining room whimsically decorated, they might feel like it is more inviting. Also, why not get a bit of attractive storage and put a few toys in there for them?