I don’t know about down in the U S but here where I am there are several hardware stores that sell 2 x 4 laminate pieces, probably from damaged sheets. I’ve used those to make table tops with including a coffee table top for my daughter. A sink cut out works too. If you’re bolting the router through the top you might want to rout out a pocket for it to sit in maybe leaving about 3/8” of material.
Someone I consider a master woodworker once told me that a master woodworker is not someone who never makes mistakes. He is someone who is able to cover them up so that no one can tell.