To have the images shrink with the screen you could add this css:
img {
width: 100%;
}
I'd make it responsive by using repeated DIV tags floated left inside of a wrapper DIV, instead of a table. That way it could move to two or one image per row depending on what will fit as the screen shrinks.
Another solution would be to just move to a single row at a particular size by adding this to the responsive css I gave you:
td {
display: block;
}