How to format multi value field as a grid?
We had a similar type of requirement to display in a grid/table layout multiple "Related" nodes rendered with a particular view mode (added with Display Suite), referenced through an Entity Reference field.
We came up with the following module: Grid Field Formatter, which is now available with a stable release.

If you look at the screenshots on the project page or the description in the content you should be able to find that it would seem to correspond to the initial requirements you described.

Feel free to let us know if I missed something, this doesn't work, or if you would have any more questions, comments or issues related with this requirement or module, I would be glad to provide more information or explain in more details.

Any more feedback, reporting, testing, comments or questions would be highly appreciated.
Thanks in advance!