I have struggled to get my 25 mo to eat reasonable quantities from the time he went onto solids. It got to the point where he refused to let me feed him with a spoon and for about a year now he has been eating everything with his fingers, including custard!
I used to get very worried about it all as his weight was getting really low. I got him checked out but everything was ok, so now I now try to relax and be grateful if he eats anything at all.
He also won't eat pork, chicken, lamb or beef, so I struggle to make sure he's getting enough protein.
Lunches tend to be easier as I give him toast or crackers(Hovis)with cheese spread, peanut butter(luckily he's not allergic), humous or mashed sardines. I also spread the toast or crackers with butter to try and get some fat into him as he's very thin.
He'll eat scrambled egg if I cook it slowly and carefully in the microwave in a small tub. I let it set into a soft lump which can then be cut up into cubes which he can pick up easily.
He will eat pots of pureed fruit with a straw.
A few other suggestions are:
chunks of cheese
halved cherry tomatoes
halved dried dates, apricots
raisins
fruit chunks
chunks of good quality sausages
fromage frais (I give him a spoon but he ends up scooping it out with his fingers!)
bread sticks
pasta
peas & corn (eaten one by one!)
baked beans !
seeds & small pieces of nuts (but supervise carefully - I'm always a bit scared that he might choke) (plus be aware of allergies)
I hope some of this helps.