I wish I could see the entire entry editor on the screen, together with as many entries of the entry table as possible.
I do too, and moving the editor to a column is how I would try to improve this if I knew Java and JavaFX Option to position editor as a vertical panel - #2 by ThiloteE
I share your complaint about the white space issue but have never understood enough about when or why it happens to do much about it. I wonder if this has anything to do with multi-line fields (the field type, not style settings such as word-wrapping).