Mrs. Mojo found this gate-leg table at Crate & Barrel. It looks kind of like this:

But when you fold it up, it gets small...

I Decided to Build One

They had a bunch of pictures on their site that made it easy-ish to work out the dimensions. I used poplar for the box & table top and pine for the gate legs. Here's how it went in my garage. Your lumber and tools may vary.

Materials List

3 ea. 12' 1 x 12 boards
3 ea. 8' 1x3 boards
3 ea. 8' 1x2 boards
2 ea. 30" piano hinges
6 ea. little table feet
1 wooden dowel, 3/8" @ 6" or longer
wood filler, brads, biscuits, & glue

Cut List (actual dimensions)

1 ea. 36 x 8 x 0.75 (top)
1 ea. 36 x 9.5 x 0.75 (bottom)
2 ea. 29 x 8 x 0.75 (sides)
4 ea. 34.5 x 2.5 x 0.75 (inside rails)
4 ea. 2.5 x 2.5 x 0.75 (inside blocks)
6 ea. 11.25 x 36 x 0.75 (for the tabletop)
2 ea. 28.875 x 1.5 x 0.75 (inboard gate legs)
2 ea. 30.5 x 1.5 x 0.75 (outboard gate legs)
6 ea. 14 x 1.5 x 0.75 (gate rails)

Tools

Circular saw or table saw
Router with chamfer, straight cut, and roundover bits
Pneumatic brad nailer and an air compressor.
Coping saw
Biscuit joiner
Clamps

What to do

Cut the tabletop boards to 36", join them with biscuits & glue, then clamp them up. I made one 72 x 33.75" tabletop and cut it in half, then I stacked them and ripped it to the correct size (36 x 28.25"). On reflection, it would be easier and better to use a big sheet of fancy plywood. I'd go thicker than 3/4" too. Maybe 5/4.

Make the top & bottom boards from the leftover 1 x 12. Drill 3/8" holes in the top & bottom. The box-top holes should be 3/8" deep and about 7/8" from each side. The box-bottom holes should go all the way through and located about 1-5/8" from each side. Both should be centered along the board's length.

Cut slots for the gate legs to pass through the bottom of the table box. Mark where the legs hit the box and make your slot a little wider than that. Use your router & straight-cut bit for a neat edge, or a little coping saw if you're steadier than I am.

Cut the slots for biscuits in the top, bottom, and sides of the table box. Depending on your biscuit joiner's design, you may not be able to do this after the braces are installed in the top & bottom, so do it now.

Cut the hand-holds in the sides next. Drill a pair of 1" holes, 3" apart, centered 5" from the top of each side. Use a coping saw to knock out the wood in between & sand it to shape. When you get the edges nice & straight, use a 1/4" roundover bit on the inside and outside of the hole for a comfy grip.

Build the braces to go in the bottom and top of the box and attach them.

There are two 1 x 3 rails that run from end to end, and a block at each end (another piece of 1 x 3 @ 2.5" long). For the bottom of the box, that's it. Glue it to the bottom and hold it in place with some brads from underneath. For the top, add some additional pieces of 1 x 3 against the box top so you can secure it with brads and not mess up your pretty tabletop.

Attach the sides to the bottom and top. Use some biscuits & glue to stick it all together. Check for square and then use some brads through the sides into the braces to hold everything in place.

Attach the table leaves to the box using the piano hinges. Do this on a flat, clean surface to avoid marring your tabletop. Chamfer the edges of the tabletop and the narrow edges of the box top.

Build the gate legs by attaching an inboard gate leg, outboard gate leg, & 3 rails. The tops of the legs should extend 3/4" above the top rail. The outboard leg should be 3/4" longer at the bottom than the inboard. Use FF biscuits and glue to hold it together. Use a rasp or handsaw to knock a little bit of material off of the front corner of the inboard leg so it will clear the piano hinge. You'll see why when you fit it later.

Drill 3/8" holes in the gate legs 3/8" deep centered in each end of the leg's inboard side. Cut some dowels to hold the gate legs in place. The top one should be about 3/4" long, and the bottom one should be about 1-1/2". Fit it together to see how it works.

Carefully dry-fit the legs and make sure you like the way they operate. When you have it fit the way you want, put a dab of glue on the bottom end of the bottom dowel and put it all in place. Hold it with a little tape until the glue dries. Cut any excess dowel flush with the bottom of the box. Once this goes together, the only way to get the gate legs out is to cut them, so fit carefully.

Install the table feet. I put 4 on the bottom of the box, plus one on each gate leg.

Fill and sand the brad holes. Sand everything smooth, particularly the tabletop. Prime & paint it and you're done.

It works!

This makes a very spacious desk that you can set up to work from home for a day then stow away when you're done. I tried it.

If I had it to do over...

I'd use heavier material for the top. The 3/4" poplar just isn't very beefy when you lean on the edge of the table. Maybe a nice 5/4" birch plywood top with some hardwood tacked to the edge.

I'd at least make the tabletop out of boards that run lengthwise, not side-to-side. I think that's giving me even more bend and stress on the biscuit joints.

Eh. Next time.