Hello,
Background color for tables was removed because of problems on dark designs, where we used white background color and some customers templates used white font color and this is real problem as we want to use as many stylesheets as we can use from customer's template.
Problem in your design is different. It looks like there are no special stylesheets for tables. If you need white background, you can simly modify yoir css files in templates/{template_name}/css/{stylesheetfile.css}.
You need to add there something like:
table { background-color:#ffffff; }
It will apply white background color for every table.
If you need apply this changes only to booking calendar and properties, you can try this css style:
#bookSetting table { background-color:#ffffff; } /* for tables in bookable item detail */
.subjectList table { background-color:#ffffff; } /* for tables in list */
We are sorry, that you have troubles with new version. New features generally bring new bugs to the system even if we always try to find them and solve them. But I can recommend you to update your booking to versions 2.1.1, 2.1.2 etc. as those versions contains only bug fixes. New features should be included in version 2.2.0., 2.3.0 etc.