Define the tables within a spreadsheet on SharePoint Online.
property DefineTables: String;
This property is used to define the ranges within a spreadsheet that will appear as tables, when using the REST API of SharePoint Online. This is not available in SharePoint On-Premise. The value is a comma-separated list of name-value pairs in the form [Table Name]=[Sheet Name]![Range]. Table Name is the name of the table you want to use for the data and will be used when issuing queries. Sheet Name is the name of the sheet within the spreadsheet and Range is the range of cells that contain the data for the table.
Here is an example DefineTables value: DefineTables="DefinedTable1=Sheet1!A1:N25,DefinedTable2=Sheet2!C3:M53"
Note: If the name of a defined table is the same as one returned by default (e.g. same name as a worksheet), the defined table will replace the default table.