Whilst it is not possible to convert Excel spreadshets (.xlsx files) to Word documents (.doc) directly, you can copy tables from the spreadsheet and paste it as a table to the Word document manually, something you can do using almost any office productive suite with support for MS Office formats. Most converters that offer xlsx to doc conversion actually do exactly this anyway, just automate it.
Open XLSX file Open DOC fileAn universal picture and document converter
Google Chrome extension for Google Drive
Office suite app for BlackBerry devices
One of the many available document converters