As there is so much white space shown .. how to prevent in interface ,extra white space
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This seems to be a record action. In the record designer, you can adjust the size of that pop-up window in 3 sizes
After adjusting the size medium if it looks odd, just use columns layout by maintaining the content in the center column and then try to adjust the value as per your need.
HiKlaus34
As Stefan mentioned, just change dialog box size to small it'll solve the issue.
This should help - https://youtu.be/Qv_R61poA9c