Make sense of a table of numbers

Help me make sense of a table. I'm not an analyst, so explain in plain words.

Where the table comes from: [for example: an ad account report / a sales export / a project estimate / an accountant's report]
What I want to understand: [for example: whether everything is OK / where the money goes / what changed this month]
The table: [attach a file or paste the data]

Go step by step:
1. What's in the table: how many rows and columns, and what each column means in plain words. If a column name is unclear, make a guess and note that it's a guess.
2. Check the data: empty cells, duplicates, odd values (negative amounts, huge numbers, dates out of order). Give the row numbers.
3. The main takeaways in 5 points: the biggest values, totals, notable changes.
4. If there's something to compare (months, products, channels), show the comparison in a small table.
5. Three questions worth asking the person who sent the table.

Rules: if you have a data analysis or code execution tool, use it to calculate instead of doing it in your head, and show how you calculated. For every total I'll base a decision on, write the formula I can enter in a spreadsheet to double-check it. Don't draw conclusions about the reasons for changes. Label them as hypotheses.