I would agree the glass is placed correctly on the table, I think what is being see is lack of shadow under the glass due to the transparency. The DoF is far to excessive, that's what is causing the top of the glass to look opaque and foggy, that and a little too much light. A couple of suggestions, may or may not work, just haven't had enough time with view, yet. Change the table top to a semi-dark wood grain with light reflection capabilities. This will help with the glass to table top thing. Depending on the material used on the table top, a small plane, out of camera view, of course, reflecting on the table well behind the glass will give an edge to the table and allow a quick fade of the background, or a transparent plane angled and set into the table to give the same effects, have not tried this one in Vue and may not work at all. Good luck you've started great.