Zurb Ink's grid requires a table.container element at the top-most level to contain rows and columns. However, it's not clear to me if there should only be one table.container for the whole email – kind of like a <body> tag. Or is it is better practice to have multiple containers, one for each section?
table.container {
margin: 0 auto;
text-align: inherit;
width: 580px;
}
Look at the CSS code for table.container It is used to create a fixed width layout which centers the content.
Now coming to your question, Look in the documentation for Reverse Row Syntax. It is a indication that tells you that you can use multiple containers if you need to restrict the full width row.
If you have a fixed width layout throughout, use table.container at the top.
If you have variable length elements, use table.container at each section if you want to restrict the width for the content.