Question: Why when delete and write take a time to run in worksheet contain text and math?

a lot of time i have this issue when i want delete something it take a lot time to show the in this worksheet it happen too what is issue it is becuase all the text are not in text modde or what? and when i want copy and past my function to place with text is write null for me, what is problem?
and why in end of my display there is two graph?

2-line-label-done.mw

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