I do not understand your last sentence...

Any Nokia 2mm charger will work (at least if you don't let the battery run all the way down...), but higher current will charge faster. Under exceptionally strenuous use, the tablet can discharge faster than the 890mA charger can charge it, but this is quite rare. With a 350mA charger, it will charge slower, and this situation will occur more often. It will work, and charge the battery to the same shutoff point, if you are not using the tablet too heavily while charging.

As alluded to before, the low current chargers may also have trouble pulling the tablet out of a very low charge state; don't let your battery run down, and that's a non-issue...