Exporting attribute table to Excel from QGIS?
QGIS v3.x
Right click on the layer in the Table of Contents (aka. legend or layer tree) and open the Save As... dialog.
Once there, click on the Format option list and choose MS Office Open XML spreadsheet [XLSX].
Note that you also have an option for Libre Office files: Open Document spreadsheet [ODS].
ORIGINAL ANSWER (no longer valid):
Install the XY Tools plugin by Richard Duivenvoorde.
Select a vector file from the ToC (that is, make it active).
Go to
Vector->XY tools->Save attribute table as Excel file.
You would need the Python library xlw installed for doing so.
To get a csv file of the attribute table, rightclick on the layer in the legend, select Save As ..., and change the file format from shapefile to CSV.
You might need to change the separator from comma to semicolon in a text editor if Excel does not like the default separator.
There's also the MMQGIS plugin which, when downloaded and installed from the toolbar (Plugins > Manage and Install Plugins...), has the tool:
Attributes Export to CSV File
