Got a Valentine's dinner coming up and need your table layout to be tables of two only? Or is it coming up to Christmas and you need to rejig to make more large tables available? Same for New Year's Day or Hogmanay, or a one-off event? We know you probably don't want to completely bin your current setup so how about creating a second restaurant area?
In restaurant areas create a new area, label it 'seasonal' or something clear to you. Go to the table layout and add some tables. (You'll need to remember them, afraid it won't let you have two table 1's!)
Then, in advanced settings go to Closed areas. Make sure you close your regular area(s) on the dates you want your seasonal area available for bookings and then vice versa, close your seasonal area off for most dates, except when you want to use it. Remember to do this after the date has passed too. Customers can always book in the future.