Navigating around tables in Word 2007 is easy. You may move from cell to cell by using the tab key. You may want to apply formatting changes to one or more cells. To choose a particular table cell, simply move your mouse to it and click on the cell. Word will highlight it and insert your cursor. You may select multiple adjacent cells in a table by clicking and dragging the mouse over the tables you want to select.
You can look online for sample proposals that you can work from, in many cases you will be able to download a template that you can work from. You will most likely find that there are dozens of sites offering hundreds of different templates to download. It may take a while, but you will find that there proposal forms that will match almost any need including yours. Take your time and select the one that best suits your needs.