Is there a table element in mosaico?
There are no table elements/blocks that you can add currently. You could try editing the source of a text block an adding manually however it sounds like this isn't ideal in this instance.

To add a table element you'd need to customise the html template itself.

If this was something you wanted to do you could use this extension which adds some additional template elements as a starting point.

https://lab.civicrm.org/MikeyMJCO/mjcomosaico