To resize a table's width and/or height, simply select any cell in the table and a set of icons will appear. Select Table properties which is the 2nd from right to left.
A range of options will display including the "Dimensions" field for you to change the width (%) and height. You will have access to other options that are important to personalize your table. Once you have set the width you want hit "Save" with the tick icon
If you are changing the width of the table to say 50%, you can make other content appear around the table as by default it is centered. To achieve this select the left or right icon at the Alignment section to move the image and text as needed. Remember to hit save to keep your changes.