A portable table assembly for facilitating initial alignment in mounting of a metallic printing plate to a magnetic plate cylinder includes a table having a top surface for supporting the metallic printing plate. A roller is mounted in the table and is exposed on the top surface for guiding the metallic printing plate along the top surface. The roller has an axis perpendicular to a line defined by a direction the metallic printing plate moves when mounting the metallic printing plate from the top surface onto the magnetic plate cylinder. An arcuate bracket is mounted to a bottom side of the table and supports the top surface at a tangent to the plate cylinder with an upper edge of the table resting on the plate cylinder. The bracket engages a locating cylinder having an axis substantially parallel to the magnetic plate cylinder and lying adjacent to the magnetic plate cylinder.