When you paste a formatted HTML table, there is no option for changing the source language or disabling other options such as "detect special numbers".
This means that in locales such as France, pasting a table containing fractional numbers (such as http://en.wikipedia.org/wiki/Density_of_air ) will randomly convert some of them into dates (because "." is not a decimal separator in French), without any way of fixing it after pasting since the original numbers are mangled beyond recognition.
When pasting unformatted text with "Paste special", you have the option of either changing the source language or leaving "Detect special numbers" unchecked. But when selecting HTML in the "Paste special" dialog, no other dialog appears and the table is pasted as if "Detect special numbers" was checked and the language set to the system locale (regardless of the actual HTML language attribute, I might add).
Confirmed, setting as enhancement.
Win 7 64-bit Version: 18.104.22.168.alpha1+
Build ID: 56019dcb79475606952a954fe732a3109441ffec
TinderBox: Win-x86@39, Branch:master, Time: 2014-10-30_07:27:11