"I know it is a real trigger for him. similarly in the summer months (and this started when I was on maternity leave) if he comes home to find washing on the line (even if there is a very valid reason why it was hung out in the afternoon so not yet dry) he gets very angry. He also got very angry if there was any food on the seat of the high chair so I now wash down the high chair and initially started not feeding my children in the high chair but elsewhere to avoid the situation."
Now that worries me. I can understand that your 3 yo cries because she wants to see her daddy. If he was just depressed, you could maybe make him understand that that is because she has not enough quality time with him. Without upsetting him, of course (it seems that he could have some emotional issues). Upsetting not in terms of angering him, but just 'speaking' to him in an emotional way. If he had emotional, bonding issues, he would display such behaviour because too must emotional stuff makes him scared, thus running away when his daughter becomes cross. But that he kicks off when he sees washing on the line... That is a problem. What does he say in such cases?
"Admitting it is very dull to bore you all with an update on the dishwasher scenario, I set everything ready to turn the dishwasher on first thing this morning but when I came to do it before leaving at 7.30am i found he had deactivated the time delay mechanism so it was effectively turned off and removed the tablet. So now I dont know what to do as he seems to be saying i dont want it on every day but without doubt at some point it will become too full at that crucial time one evening in the future and the dinner things wont fit in.
I have tried putting it on in the evening but the shortest cycle is about 2 hours so am unpacking it about 11.30pm or midnight which is fine but not ideal. Maybe I just put the dishwasher on the minute i get home from work at 6.30pm, it finishes around 8.30pm which is around our dinner time and I can empty just before we eat then eat my dinner and refill the dishwasher then."
That worries me too. I would just ask why he removed it and demand it back. It is surely my dishwasher too so I have as much say over it as he. 50% of material things in this marriage are yours, so he gives it back. And tell him you really do not see how that could make anything clear.
You should never ever ever ever change your routine to avoid his anger. If he is an abuser, he would relish that. Can you see how ridiculous that is? I mean, if he is stressed and kicks off on one about a dishwasher, that could still be excused, but that you start to avoid the highchair because he may kick off on one becuse there is food on it... That starts to become a little crazy. If he gets angry, for whatever reason, that is his problem not yours.
If he truly starts shouting so you can hear it in the bedroom, I would try not to listen and to carry on as normal.
If he wishes to control you, he will soon get angrier and try something else if that doesn't work anymore. If he does, walk away, even if it is with dcs.
I think it is sad that he doesn't want to help you with the children in the evening, but maybe (just maybe) he is just very tired. It doesn't necessarily need to be malicious. It may be, though. Particularly the display thing, the highchair and the washing line situations are suspicious. Has he ever been violent (slapping you, breaking things, banging things, I don't know)?
But please bear in mind that I may be mistaken about this.
Maybe it would be helpful if you were to think of whether he has ever expressed a desire for you not to work or for you not to meet any friends/family any longer. Abusers normally want to isolate their 'victims' so they can control them better.
At any rate, what you are thinking is not fair to yourself, nor is he being fair to you.