Can I add standing cocktail tables with no seats?

Yes. The 30-inch cocktail preset (60 cm poseur in metric) has no seats: guests are not assigned to it and it never counts as seating. Use it for the cocktail hour or the bar area on the same plan.

A cocktail table does count as a table on the free plan. If you only want to show where the high tables stand, a furniture item does the same job.