Free file sharing websites are very useful if you have pretty large files to share that exceeds 20 MB in size and thus cannot be sent over emails. With Gmail, you can send and receive messages up to 25 megabytes (MB) in size but you may not be able to send larger attachments to contacts who use other email services with smaller attachment limits.
Google Drive from Google and Skydrive from Microsoft can also be used for file sharing but you need to have an account and there is limit to the size of the file that your account can keep. Moreover it can be easily accessed by anyone who knows the direct path of the file.
However followoing are some websites that offers free online file sharing for large files without sign up. They allow to you share files with your friends or colleagues, without having to worry about the file size or security issues.
PDF to Excel (XLS or XLSX) conversion is not as frequently required as Excel to PDF and hence the online conversion tools for the latter are easily available but not for the former. 
Webcam Video recording is now extremely easy and simple as You Tube has now made this facility available for it's users for free. 
Today's smart search engines give very high importance to load time of a website beside considering other important factors that enhances user experience. Hence it is important to understand how fast is the performance of your website and what are the areas that needs improvement.
The periodic table is a table of the chemical elements in which the elements are arranged by order of atomic number in such a way that the chemical properties of the elements can easily be understood. 
There are many file conversion software's and websites available online for converting your power point presentation to video formats. As a trial, these softwares and websites let you do the conversion for free but the resulting video contains their own advertisement as watermark which makes your video look unprofessional. 
