This plugin holds and summarizes a variety of datasets including spreadsheet rows and columns. A factory will make data items from .csv files dropped from the user's desktop.
Materials Summary
See GitHub 
for plugin source.
Data items are rendered as a thumbnail with a large bold summary supplemented with an editable caption.
Double-click on the caption to open the text editor.
The format of the large bold summary gives an indication of the shape and size of the dataset.
Num x Num summarizes a table of rows x columns.
Num / Num summarizes a graph with nodes / arcs.
Double-click on the large bold readout to examine the data item in its native json format.
Scrubbing
Scrubbing (hovering back and forth) across a dataset shows details about a dataset's contents. The example shows column averages for each of the available columns. When a column can't be averaged, it shows NaN, short for not-a-number.
Similar datasets will track the scrubbing showing values with the same column name, if any. See Radar Data in Data Plugins for sample data with these columns.
Scrubbing does not work in every browser.
Refreshing a page will restore the display to the initial summary.
Importing Data
Data can be imported into wiki by dragging .csv files from the desktop. Not every browser or operating system handle drag-and-drop.
Create a factory (drop-zone) by clicking the [+] button at the bottom of a page. See About Factory Plugin. Drag a .csv file to the factory (gray rectangle) and drop it to complete the import.
Sometimes unrecognized files will create a stub data item with only information about the file but not the file contents. This means the particular file format is not yet supported.
Tip: keep your .csv file simple. Use only one row for column headings. Don't use merged cells or exotic formatting. Some programs write a various kinds of .csv files. Try alternatives on a temporary page until you find the one that works.