Actually, my kids prefer to use the track to make their tracks on the floor and skip the table. Little kids like to sit on the floor to play anyway, and older kids can make a lot more complicated designs when they don't have to stay on the table. We've been slowly adding to a set for our ds, letting friends and family give a train or track at birthdays and Christmas, its been great, the train set stays fresh as the new things come in, and it has grown with him. Toddlers really are happy with just an oval to go around, they don't need the complicated stuff, and actually my ds (age 3) will take apart the more complicated stuff his sister makes for him, he'd rather just have a "loop" as he calls it. He's big enough now he likes for his loop to have a tunnel or something, but even a figure 8 is too complicated to be played with for long.
Also- if you glue the track down, you loose the play value of your son figuring out how to put together a track later, a great problem sovling skill and construction activity.
Laura, Mama to Mya 7/02, Ian 6/07 and Anna 8/09