My EdgeStar Icemaker IB450SS/SSP is making sheets of ice, rather than individual cubes. Is this normal?    

Yes, your icemaker is working as designed.  The IB450SS/SSP uses a sheet/tray method for creating ice cubes.  This is the same manner in which commercial ice makers found in restaurants and hotels create ice.  When the ice formation cycle completes, the sheets of ice are dropped into the storage bin.  The process of releasing the ice into the bin typically breaks most of the ice sheet into individual cubes.  It is important to note however that as the ice bucket fills, the sheets of ice may land more gently onto the previously harvested ice and therefore may not break as easily.  Simply use the ice scoop that shipped with your unit to break the ice into cubes as needed.  This process should require very little effort as the sheets are already formed properly to break into cubes.