I am still confused about this question. I am posting this just to understand better what is wrong again with using `GraphicsGrid` or `Magnify` as was suggested above? Here is just an example. Why this does not work? It is also easy to use `ItemSize` to control the size of each entry in the `GraphicsGrid` if needed.
SetDirectory[NotebookDirectory[]];
Manipulate[
s = Which[method == "GraphicsGrid",
GraphicsGrid[tbl, Frame -> All, Spacings -> {.5, .5},ImageSize -> n],
method == "Magnify", Magnify[Grid[tbl, Frame -> All], n/500]
],
{{n, 300, "how big?"}, 200, 1000, 10, Appearance -> "Labeled"},
{{method, "GraphicsGrid"}, {"Magnify", "GraphicsGrid"}},
Button["Export to PDF", Export["s.pdf", s]],
Initialization :>
(
tbl = Table[ListPlot[RandomReal[{0, 1}, 10],Joined->True,ImageSize->100], {3}, {3}]
)
]
