Hi Jsb2228,
Thank you for sharing the experience with us.
Regarding the first issue, I undertsand it happens when you format text in a table in OneNote.
Have you tried to create a new page, insert the table, then see if the font in the table cell keeps changing? You may also try a different section or different notebook to check the outcome. This help you narrow down if issue only appears in a spcific page.
You may also click the 3 dots(Settings and More) in upper-right corner>Setting>Options, ensure the Default Font is Calibri, then use Format Painer to apply Calibri to the affected texts, after the change is syned, see if texts still revert to Times New Roman.
I also suggest you try repairing OneNote with steps below:
Quit OneNote, open Windows Settings>Apps>Apps and Features>scroll down and find OneNote, click Advanced options>click Repair. After that, restart OneNote and see if issue happens.
If issue persists, I'd like to cofirm information below to further troubleshoot the issue:
1.What is your OneNote version?
2.Do you have the issue before? What changes have you made before this issue? (Update Windows or install any program?)
3.If you use a different font(not Calibri), does the text keeps reverting back to Times New Roman?
Regarding the second question, unfortunatelly, OneNote for Windows 10 doesn't have the formatting options as you want, neither the Page numbering feature. Really sorry for the inconvenience cause by this.
(But based on my test, after I create a table in Excel app, I can directly copy and paste(contrl+V) the table in OneNote and edit texts in table cells.)
I recommend and encourage you share your valuable feedback by clicking the 3 dots(Settings and More)>Feedback in OneNote, this would be the best way to let the OneNote developers know about your requirement and help imprving the product.
Your understanding is highly appreciated.
In addition, I test in OneNote 2016 to insert a table and format it, I find that if I edit in a table cell and right click it, there is an option "Convert to Excel spreadsheet".
If I select this option and try editing the table, Excel applciation opens and I can format the table in Excel. When saving the worksheet, changes in table will show in OneNote 2016.
You may also have a try and see if this can be a workaround.
To install OneNote 2016, you may refer to this article Install or reinstall OneNote 2016 for Windows
[Updated by Tina Chen MSFT, 2:13 AM, February 7, 2020]
Best regards,
Tina