create a break during experiment

There are two things to mention here:

1) Yes, you can do this, just break the same task into different blocks. If you have the same task/table but in different blocks, I think the all_before_repeat will still work

2) Try it out. For this I recommend the following. Make a copy of your experiment, but now just let the trials run really fast. You can simply comment out the sound files and you can make the "delay" really short, say 30 ms. For the readkey (if you have those) also set the maximum wait time to, say, 10 ms. That way, things will run realy fast and you can check whether all the trials have been done in an order (e.g., without repeat) that you like. Once you are happy you can use your original experiment.

Always test and try your experiment before you run it...