Dear Yaaaaaaaan,
Let me tell you how I manage our classes of 16-40 students and you can decide if it's helpful to you or not.
On a daily basis we have question time. 2 or 3 students are randomly selected to answer some questions like: What's your name? How are you today? and What cartoon do you like? This takes about 4 or 5 minutes.
After that, we usually do a skit. The skits are entertaining for the people doing the skit as well as the people watching. As the teacher, you can help the students say their lines.
We also do practice where the students listen and repeat. Many subjects adapt well to using TPR (total physical response) in which case, the students are moving and talking. During the practice you can get an overall sense of how the students are doing. for example, If you say "2 apples" but hear "two apple," rabbit versus labbit etc, you can correct the students.
After practice we play games. And there is no reason not mix a large variety of games into your class. Games can be played in smaller groups. You have 23 students so 5 groups of 4 and one group of 3. The important thing is to have a large repertoire of games so that thing stay interesting. You also have to think about where the students are in their lesson. Think about this:
Many of the games for large groups only require the student to listen and repeat; The Fruit Basket game is one example. These kinds of games are good for the first time that children have the lesson because they haven't been exposed to the English enough to be able to repeat it on their own. After the children are comfortable with the English then break them into smaller groups to play. Then you can walk between the groups and make sure they're doing OK.
Mostly keep the pace fast and fun.
Anyways, I hope that helps.
Bill Ralens
www.naruhodo-eigo.com