These things cause foaming at random times, at least for me. Whenever I've had to use these, I fill about 8 bottles, I put the caps next to each bottle, upside down. I place however many tabs I want in each bottle into the cap. So then I have 8 filled bottles, each with an upside down cap next to them with tabs in them. I dump the tabs into the filled bottle and cap it real quick, going down the line. Then repeat with about 8 more bottles until I'm done.
If you have foaming issues, that may save you some headache. The numbers of tabs per bottle that you listed sounds right, as well as UpstateMike's 1L estimate.