Yes there is a simple way: don't use XML. XML is really only for setting up a frame that never changes, but you can do 99.9% of all frame related things in Lua, which is infinitely easier to read, and more importantly, debug.
In your ADDON_LOADED function (see my other post), assuming your saved variables in the ToC are called HistoriaDB, it should look something like this:
Code:
function private_table.eventFrame:ADDON_LOADED(AddOn)
if not AddOn == MyAddOn then
return
end
private_table.eventFrame:UnregisterEvent("ADDON_LOADED")
HistoriaDB = HistoriaDB or {}
end
function private_table.eventFrame:PLAYER_LEVEL_UP(player_level)
HistoriaDB["player"] = {name = UnitName("player"), level = player_level, current_time = GetTime()}
end