I think I found the answer to my first question on the Fedco Seeds site:

"Be My Baby Gene Pool Cherry Tomato OG (65 days) Open-pollinated. Ind. This productive cherry is the ongoing result of a cross of three famous tomatoes: an heirloom potato-leaf beefsteak and two cherries, one orange and one red. The crossing and selection process began in 1997. Although it was selected for a red cherry with regular tomato foliage, a few plants will still be potato-leaved. Rogue them out because their flavor is not as desirable as the rest. The grape tomato in its background lends a rich sweet flavor somewhat akin to that of Sweet Baby Girl, which it replaced. Bred by Relentless. 2007. OT, CO-certified."

I still don't know if a large tomato can result from crosses involving cherries.

Jim

I answered in the tomato forum.

The F1 will not likely produce a large fruit.

In later generations, if one starts to select for fasciated, multilocular fruits, one can get larger fruits. Fasciated/multilocular meaning beefsteak types.