I have built a lot of stuff with wood pallets. The biggest thing to consider for a table is that most pallets have been treated with chemicals like formaldehyde. Some are stamped with HT (heat treated) aka kiln dried and are generally safer. The bottom line though...is you never know where the pallets have been, what they have transported, or what they have been treated with to withstand wet environments.
If you are going to build a table I would recommend buying wood for the legs and the apron, since most pallets are not made with 4x4 and are far from square by the time they are retired. The process of removing the wood can be tricky. I use a reciprocating saw and cut the nail. Most pallets have ribbed nails so are a pain in the A$# to pull out!
I would use Ana's farmhouse table plan to make the base with bought wood to ensure a nice level and square base and then use the pallet boards to make the top!
I just recently built a farm table. Here is a link to how I did it.
Let me know if I can be of anymore help!
Just delivered my new Kentwood bed to my grandson. He loves it. I came out wonderful. The only trouble I had is I had to raise the height so a trondle bed woud fit under it. Also the rail were an 3/16 inch short. So had to move my bed hardware out so I could fit the bed spring. I should have measured a little more closely. Besides using bed hardware I also used pocket jigs to hold the rails. Great bed plan on making a couple of more. It cost me about $200.