Hickory: You cannot import a tome into BG2. At the start, every single item is stripped from your inventory.
At least in BG2 classic:
You actually can import the tome; it's just stripped from your inventory before the game really starts. You can, however, access the inventory before the starting cut-scene happens if you're fast enough, and then drop the tome (or anything else you want to keep).
One thing I am wondering: If you happen to have one of the items that would normally transfer (in the sense of it appearing instead of some early-game item in the starter dungeon), and you drop it before the game takes it away, can you get a second copy of the item? Or will the game think you hadn't imported the item and give you the default item at that point?
sorvo2750: I know it raises you 1 point but in the case of the fighting classes will it take you to 19 if you have 18/whatever like in original BG or will it just take you to the next 18/whatever like if you cheated one into original BGII?
Hickory: Strength tomes raise you one full point. The exceptional strength bonuses are just that, bonuses to 18 STR. So yes, you go from 18/xx to 19.
It's worth noting that what you said is *not* true in Icewind Dale classic. There, using a stat tome will only give you the next 18/whatever. This same difference applies to the Draw Upon Holy Might; a level 9 cleric with 18 Strength will only get up to 18/76 Strength when casting the spell (in BG2, it would be 21).