You use the "formatValue" to return any text/html you want:

Documentation: Table formatValue

Best regards,

The picture could not display if you put the real path ( server path) like above. It should be the url: something like this:

...
"columns"=>array(
    "image"=>array(
        "formatValue"=>"<img src='http://www.myhost/images/@value' />"
    )
    ...
)

So you have "image" column contain image name such as "picture.png", on each rows, the value will be fill into the @value so you will have full image src. It result in displaying the image inside table cell.

Hope my explanation is good.