OK...
Come and Get it Street Store and any outdoor chair can go into your inventory. Not the tarp, sadly :(
You can stock the table with anything that will go into a sim's inventory. I just grabbed all the books off a bookshelf and dragged them into my sim's inventory for my test.
To setup, drag the table out of the inventory and then you need to stock the table. To do this, open the sims inventory and drag your stuff to the table.
Next, select the table and select stock table, then tend table, then start sale.