Place all your images you want in the Gallery into a single folder. Use the Action Palette's Select an image drop down to select an image in the folder, hit the Process Gallery button and off you go! These images can be a JPEG*, TIFF, Photoshop file or PNG (or even a mixture).
The images will be automatically scaled to fit the space in the table, as well as to the size of the Large Image Size. This is where GraphicConverter comes into play.
The dimensions are guides - the Action will do a function similar to Freeway's Scale and Pad when resizing the pictures. Your original images are not touched - copies are created for the thumbnails and full size gallery images.
If the image is a taller than it is wide, then the long dimension will become the height rather than the width of the final image.
Use the Process Gallery button to create the gallery images. The Action will tell you when it thinks this is necessary. The status of the gallery is shown under this button. For example, applying themes to the gallery will require the images to be reprocessed. If you change the size of the table, you should also reprocess the gallery as the size of the thumbnails will be different.
You should click on this button each time you change the contents of the images folder. Actions cannot detect this kind of change automatically.
When the Actions palette is used or opened, It will check the number of images in the folder and compare that number with how many images it knows about. If the two numbers differ, it will display a message telling you to click on the Process Gallery.
If you wish to have more than one gallery, you should store the images for each in a different folder. You can only have one gallery on a page.
It can take a long time to build a Gallery,especially if you max it out with 250 images! It's better that you have control over this, rather than let Freeway decide to build every image when the page publishes.
* NB - JPEGs must have RGB channels. Problems have arisen with other types of JPEGs, especially grey scales.