CO2Tables 2.0 was available to download from the developer's website when we last checked. We cannot confirm if there is a free download of this software available. CO2Tables belongs to Office Tools. The most popular version among CO2Tables users is 2.0. The actual developer of the program is MegaWatSoft. We recommend checking the downloaded files with any free antivirus.
From the developer:
The CO2 Tables is a Microsoft Office Excel Add-In library that calculates many thermodynamic and transport properties of CO2(carbon dioxide). This software will allow 11 different combinations of input variables that can be used for calculations. Input variables that can be used are: enthalpy, temperature, pressure, entropy, internal energy, volume and quality (vapor mass fraction).
You may want to check out more software, such as AcadCalc, iUnit or Pico Diagnostics, which might be related to CO2Tables.