It is funny to see VME boards considered "large" (though there were options to allow them to be huge). The name is "VersaModules European format" replacing the 370x230mm VersaBus boards with 233.35x160mm 6U for typical VME boards. Simple i/o could use 3U (100x160mm) boards. This reduction was possible because of denser chips, specially PALs.
Very large boards (9U height and/or 340mm or more depth) were used later, as I mentioned above. But I consider them the exception.
Apple wanted an ISA-like form factor so the cards became 101.6mm high and between 177.8 and 327mm deep. So a bit smaller, but not that much than more typical VME boards. The less squarish form factor does make routing signals to the connector a little more complicated.