Very cool items.
I think the four digit number represents some kind of serial number for the ticket. Not completely sure but I think all wagers were $2 back then and "straight" represented a win bet. The number on the far right was likely the horse number in that race.
So each ticket was likely a $2 win bet on the #2 horse in each of the races.
The typewritten page looks like someone's handicapping from the Morning Telegraph, which was the East Coast version of the Daily Racing Form. The series of numbers were probably the picks from the various handicappers printed in the Telegraph.
I don't collect much any more but I can point you to a couple of resources that might be of help:
The Keeneland Library
National Museum of Racing