I create a new Workbook session and change some values. After done, I would like to download the changed workbook. However the item download/convert api does not allow to download a workbook in a session, so I always get back the original, unchanged workbook.
So please allow to download a workbook in a session.

Create a new workbook

The API currently has no way to change the tab color for a worksheet.

The API currently has no way to insert images into a worksheet.

Text orientation, for example, rotate the text vertically, is required by the user.

Currently, when creating a new table in a worksheet using the instructions at https://docs.microsoft.com/en-us/graph/api/tablecollection-add?view=graph-rest-1.0&tabs=http, you can't provide table column header names. I currently have to:
- Create a table POST /tables/add (address e.g. A1:G1 for 7 columns)
- Get table colums with GET /tables/{ID}/columns
- Patch each column with a column name PATCH /tables/{ID}/columns/{ID} (7x in this case)

Would be great if we could provide the column names on table creation already.

As Graph API user, I want an API to query the status of the Excel file being edited on OneDrive, so that I am able to delete it once my work is done. For example, we use Graph API to delete the file, but it failed due to “locked”. Another example is that the UsedRange API returns the range which is not updated to the latest.

Refer https://docs.microsoft.com/en-us/graph/api/range-usedrange?view=graph-rest-beta&tabs=cs

Our application work-flow is using the Graph API to upload the excel file to OneDrive, open it with internet browser (Internet Explorer, Edge, chrome ...) Then the user changes the content of Excel file, closed the browser, and our code downloads the Excel file from OneDrive.

Currently there is no Graph API to support using any internet browser to open Excel file on OneDrive.

Our application is heavily dependent on the data validation feature, especially using the list validation. There is no Graph API to set the validation for a given range.

Beta now adds ability to GET Calculation Mode and to Calculate, but we would like to also SET the Calculation Mode. This should allow us to improve performance of setting multiple ranges (without dependsOn and small batches).

https://stackoverflow.com/questions/55853198/graph-excel-api-how-to-set-calculation-mode-to-improve-performance/56277975#56277975

It would be nice we could have the same functionality in Microsoft Graph as the freeze panes in Excel worksheets. It's been commonly available in other APIs for Office clients and add-ins.

very challenging at the beggining stilll quite a ways to go but very efficent Thank You Microsoft

Be able to retrieve thumbnails of Excel documents. This feature works great with Word documents and other types, but really needs to expanded to work with excel

With Azure AD 2.0 Endpoint, Graph API now supports OneDrive personal (in addition to OneDrive for Business). However the Excel API does not yet support OneDrive personal -- we would like it to.
See http://stackoverflow.com/questions/40121236/graph-excel-rest-api-azure-ad-2-0-endpoint-is-onedrive-personal-supported

Detailed Question:
https://stackoverflow.com/questions/52245424/how-to-create-custom-input-output-functions-in-microsoft-graph-excel-api/52246534

For Example :

Cells A1 to A10 has some data
Cell B1 is an input field
Cell C1 is an output field whose value is a functions of A:1 to A:10 and B1 ex: C1 = SUM(A1:A10)/B1

Is is possible to use Microsoft graph API(or any other api) to send the input data in the form on HTTP request parameter and get the result as the response of the request ?

An Ideal request-response would look something like :
http://path-to-workbook/path-to-response-data?parameterB1=someNumericValue
Response:
{
C1: <result of calculation>
}

I would like to run Excel Macros through the Microsoft Graph Excel API. I read through the documentation but couldn't find anything related to Macros. Is there a way of executing my Excel Macros somehow via Microsoft Graph?

Since Excel 2013 there has been a limit of 255 on the Chart Axis Interval value, this needs increasing again as per Excel 2010 and earlier as it is currently impossible to control sensible axis labels in large datasets - thanks.