Spreadsheets have a "table mode" which basically reduces the UI of the spreadsheet so you can't see the row headers, etc. Table mode makes a spreadsheet integrate more cleanly in to your document, but spreadsheets in "table mode" have all of the same functionality as spreadsheets in Quip including formulas and functions, etc.
To switch between spreadsheet and table mode:
1. Place your cursor in the relevant spreadsheet.
2. Open the Spreadsheet menu.
3. Select Sheet Mode.
Full Screen Spreadsheet Mode
Quip Spreadsheets can either be embedded in a document or you can create a "full screen" spreadsheet (like a traditional spreadsheet in excel or Google Sheets). If you are viewing a spreadsheet in a document and would like to be able to see more of the data (rather than scrolling), you can click the button in the top left corner.
That will only change the view for you -- everyone else will still see the spreadsheet inside the document. If you'd like everyone to see the full screen spreadsheet, you can head over to the gear menu in the top right corner of the document, and choose "spreadsheet" from the "Themes" menu.