Sims 4 Is there a way for toddlers to sit at the table without a high chair?

Not at the table, but the ones that are more trained climb on a bench in the bar room I've made, and can eat from there. Might, or might not work the same with the sofa. I think resizing is for looks only LOL. They won't use the item named something they can't use. And yeah others can sit on the same bench and talk with them, I saw it this morning. I think it's a styled Corsican bar from Cat's and Dogs. But probably any bench would do the same thing. 

@AshleyL9803 , while this isn't quite what you were asking for, I usually just have everyone eat together while watching TV! This way Toddlers can join them without it being weird! 😀
However, I realize you might not like that idea. We would need something like a booster seat in the game.🤔  I don't know if they are adding anything like that to the game in the new Grow Together Expansion Pack that is coming out soon, but it is possible!  I will be on the lookout for this as more information on that pack is revealed! 🤞 

Maybe this Mod by Around the Sims 4 is something you're looking for:

https://sims4.aroundthesims3.com/objects/room_kids_20.shtml

@AshleyL9803 If you set one of the chairs back slightly at an angle so it’s “at” the table but not actually attached to the table, toddlers can climb into it to sit. They’ll hold the plate on their lap though.