Adjust tab key function and enter key function in Excel

Have switched over from Lotus 123. In that program I could adjust the
functionality of the tab and enter keys on my keyboard. For example, when I
hit enter key i could direct which direction the cursor would go to next ie
to the right one cell, down one cell, etc Also when I hit the tab key the
cursor would move one page to the right. A really handy feature in large
spreadsheets. But in Excel the tab key only moves one position to the
right....that's a useless function. How do I change these?