Use a vacumn easel.
there must be some on ebay or craigs list
If you are handy , and I mean handy you can make one yourself.
Keep the motar/pump off your enlarging table and away from the enlarger .
These were necessary tools in the Photo Comp Days before Photoshop, I have used wall mural vacumns for giant murals right down to 8x10 inch V - easels.
If you get one then black magnets strips will allow you to make an edge for aligning the paper into place and away you go.