Using the D&D Statblock template, I've inserted a table into one of the free text areas, every time I save the sheet and come back, WA has entered in one blank line between whatever text was on top of the table, and the table itself. I'm not sure if this is limited to the character page tables or not
Character view > Create Character > choose a typable field > Create a header font > Create a table below it > Fill the table > Save > Choose edit sheet > more spaces will exist (you can also see spaces propgating in the view sheet view)
Sadly this is not easy to fix at all. If you are using the BBcode make sure there no spaces between your td, tr,th,table tags and it will fix it