I recently modified my portable table saw to replace the left extension table with a jig saw table. The hinged table design allows easy access to change jig saw blades.
Since table saws vary in construction details, you will need to modify the construction approach as necessary for your table saw.
I got the idea for this as I was constructing a hinged router table for my table saw. I wanted to be able to have a jig saw table that would be able to use my table saw fence for cuts. With the router table on the right side, why not use the left side for a jig saw (as long as the blade can be quickly and easily removed)?
I purchased a used Bosch 1590EVS jig saw from someone off of Craigslist for $75 as this jig saw has excellent reviews and has an easily removable blade. If you already have a jig saw, you should be be to use it, although you may want to consider getting a jig saw that has an easily removable blade.
I also wanted a smooth white formica top, but I wanted to use a solid wood base vs a particle board base, and I found a white formica table top at the Restore for $17 that I could cut up and use for the jig saw.
With the blade pulled up to its highest point, it is about 1-3/4" tall - which is more than enough to cut 3/4" plywood, etc. With the 3/4" thick formica top, and the jigsaw recessed a little more than 1/4" so, I should be losing only about 1/2" from the cut stroke.
I have just put the jig saw table into service and it appears to functioning just fine. I'll provide more feedback as I use it over time.
For more details on the construction, see the following Instructable: