Weave.ly has its own spreadsheet-like data editor to make it easier to handle real data in your prototypes. You can access this editor by clicking on the Data tab in the top navigation bar inside the editor.
Creating tables can be done by clicking on the + symbol at the bottom of the editor (or clicking on the big + symbol if no table has yet been created. You can rename or delete a table by right clicking on its tab.
Adding or removing columns can be done by right clicking on table header. Similarly you can rename a column or change its datatype by respectively double clicking on its name or datatype.
Rows can be added by right clicking outside of the table header. You can either create rows manually (i.e. one by one) or import data from a .csv file. To delete a row you’ll first need to select it by left clicking after which you can right click on delete it.