Scarlett - yes, you are completely right to be miffed. Even in secondary school parents are supposed to be informed what homework has been set - let alone Year 4!
I think spellings and tables have been a victim of poor communication throughout my DCren's time at school. When DD was in Year 2 learning tables was purely optional and children had to ask to be tested on them! Many parents did not even realise what tables their children could or should be learning and were shocked when the end of year report came out telling them that their children were struggling in numeracy. DS had a tables test every week in September and half of October (he's in Year 2) but hasn't done tables at all since - he says he doesn't even use them in school!
Spellings have been an issue for DS in Year 2 largely because they are taught in groups rather than by their own class teacher and the spelling books seem to appear and disappear and spend half the week sitting on a shelf somewhere rather than handed out to the children. Last week DS got 9/10 on a spelling test (he has always got 10/10 before now - he's one of those freaky 'natural' spellers) because he never saw the list before the test and misheard the word 'crumple' for 'crumble' (or vice versa) - another very bright child got 0/10 because he spelled all the words ending 'el' rather than 'le' - a mistake he would not have made if he had ever got to see the list!
We should get a termly letter saying what topics will be covered (and mentioning spellings and reading aloud) - but, come to think of it, I haven't had one for either class since September - maybe we should both go ask for one, Scarlett - I'm sure you should have got one too.
When I was a child I had fun and played with my friends at the weekends and had a miserable time learning to read and write during the week - maybe the situation has just been reversed in this generation.