Did you have a look to this article ?
I think a spreadsheet is not supported.
If you want to send a copy of your spreadsheet, you need to use a workaround
If you create a report, you have the possibility to create a template automatically, with a table title, and a Start/End expression looping on the rows of your spreadsheet.
The requirement is to use a parent table, and designate your current table as a child from this one.
Then, use Start/End on the Child (=your table).
On your datas:
create a table, fictitious for you. Let’s call this one Parent.
one key-column, one row, one value : k1.
on your table, add a column “RelatedParent” and set type “REF”, source : the fictitious one, Parent.
Set the same value k1 on the whole column rows.
On your editor:
Behavior/Report/Add a new Report
…for table… ==> choose Parent
if this is true… ==> choose condition (have a look on triggered actions posts in the community)
Run these tasks… ==> choose “Send an email” then untick the “use default content”
Save (blue button on right-top of the windows), in order to run some (maybe) missing options.
Finally, chose Attachment type : PDF, then click on the “Create” button on the right side of “attachment template”.
That will create a file template, and you can display it and modify it.
Can you give it a try and let us know if that works for you ?