There are commercial alternatives to this table but they tend to be rather pricey. Making it yourself with save you some money and of course be much more fun. The project will probably take about 3 hours to complete. Maybe a little more if you have to work on the crates before they are presentable.
Step 1: Go shopping
Before getting started you probably need to go shopping. This is what you need.
1. Four crates
2. Spare wood or one extra crate for material
3. Wood tint for the base. Try to match the color of the crates but it doesn't have to be perfect. The base will be underneath.
4. Mounting angles (see later steps)
5. Short furniture/bed legs
Step 2: Mount crates
Screw the four crates together short-en on long-end like in the picture. You may have to be a little creative and do small adjustments as the crates may not be 100% symetrical.
Step 3: Make the frame
Take measurements on the crates and make a square frame as in the picture. Make it a little smaller (about 5-10 cm) than the crates so the frame won't be too visible. A cross in the middle was added after the pic (to make it stronger. See next step.
Step 4: Tint
Tint the frame
Step 5: Screw the legs onto the frame
Step 6: Attach frame to crates
If you have a nicer side of crates, make sure it it face-down then screw the frame onto the crates. Use screws of a length that won't go all the way through.
Step 7: The hole in the middle
There are lot's of things you can do with the center hole. E. g. stick a lamp in it, make a table top if you material from a fith crate or as in this example make a small mini table about 5 cm lower than the top of the crates. The U-frame rests on the floor and the tree boards across make the table. The boards are tinted in the same colour as the base.