Selling Pies

anything that can sit on top the table can be sold. some things can sit on top but cant go in the inventory for some reason.

You must put the pies into the sales table's inventory, then just click on Stock and the pies will appear on the table.
You can only put the pies on there if the table is placed on the lot. Otherwise do the way I told you.

I Cant seem to put anything in the inventory. I've tried it a few different ways. I can put the cakes atop the table, and begin a yard sale but the cakes don't register as for sale. Whenever I try and drag the cakes to the inventory I see the little red circle with a cross.

This might be a mod conflict if you are using mods in your game. Look for mods that might be using the same resources as the table you are using. Such as any mods that modify food, cooking, retail perks, etc. You can try repairing your game or resetting (debug) the table in question. Bring up the cheat bar and type in testingcheats on then press enter and if that fails, use testingcheats true, and press enter. Once testing cheats is activated click on the table then click on the 'reset object' option. Good luck. :)