Thank you for your post.
Under Windows, use Ctrl-Shift-V to paste without style. Under Mac OS X, use Command-Option-Shift-V. This will paste the copied information without style.
If the data has already been pasted with an active style, then use Ctrl-Z under Windows, or Command-Z under Mac OS X to undo the style.
If the pasted data is already committed, then copy the entire contents to the clipboard and press Ctrl-Shift-V or Command-Option-Shift-V.
It seems odd that theres no way of setting a default font / size / formatting for all cells ?
As if your entering hundreds of cells of data expecting a member of staff / user to - Command-Option-Shift-V each time seems crazy ?
If you have several records where the font, font size, style, etc. is different than the default value for the field, then use Replace Field Contents with the calculation: TextFormatRemove ( <field name> )
If you always want the users to enter the default settings, then change the field Options to include Auto-Enter Calculation: TextFormatRemove ( Self )
Be sure to uncheck the option "Do not replace existing value of field (if any)".