Purchased an outside table made out of Acacia wood.

Here are a few options for you - love Kamoda grills! Hope to get one some day. Great project. Enjoy!

http://www.woodmagazine.com/woodworking-tips/techniques/routing/large-holes-in-5-easy-steps

https://www.wwgoa.com/article/workaround-make-any-size-hole/

https://www.familyhandyman.com/tools/saws/how-to-properly-use-a-hole-saw/view-all/

Jig Saw --- start with drilling a hole large enough to insert the blade --measure carefully and don't force the cut - slow and easy. Use a file to remove any rough edges; sand.

electric drill (battery) with round drill attachment, they look like biscuit cutters (but smaller). Be sure to anchor the bottom with a hole or metal mount to stabilize the grill.

A jig saw is what my hubby uses and finishes any uneven spots with a dremel tool.

I agree on the jigsaw. With a drill for a pilot hole to start in. Also, if you want to keep the finish of the table, be sure to put painters tape on both sides of it, where you are cutting. Might have to trace the outline over the tape too, to follow with the jigsaw.