So I've managed to make an html site for a business too, and I'm using table POST data for a php script. Everything works fine but my table spacing is no efficient. I'd like to keep the arrangement of tables all within the same form, but I would prefer that they are spread across the screen in columns rather than rows.
this is more of a CSS question than HTML. You will have to set a width on the tables you want side by side. Make their width 50% each or less and either float them or use display: inline-block. As long as you put the input fields inside of a <form> tag, the submission will pass all the data.
Also you should not be using tables for something other than tabular data. I don't know what kind of data you are putting into the tables but if it's just a form with input boxes and buttons you should use divs instead. It will significantly cut down on the markup.