Shamelessly copied from visual pinball forums

EMs

Bally 70s EM - standard = 20.25" x 41.00"
G 70s EM - standard = 20.25" x 41.00"

Early SSs

*G System 1 - standard = 20.25" x 42.00"
Early SS Stern - widebody = 23.875" x 45.00"
Zaccaria - standard SS - 20.25" x 42.00"
*Pre WMS Bally - standard = 20.25" x 42.00"
*Pre WMS Bally - widebody = 26.75" x 40.50"
*WMS System 1-11 - standard = 20.25" x 42.00"
WMS System 1-11 - widebody = 27.00" x 42.00"
*Atari - widebody = 27.00" x 45.00"
*G System 80 - standard = 23.75" x 46.50"
*G System 80 - widebody = 26.75" x 46.50"

Modern SSs

Capcom tables = 20.25" x 46.00"
*Data East - standard = 20.25" x 46.00"
Data East - widebody = 25.00" x 51.75"
*Safecracker = 16.50" x 41.50"
*WPC (through 1987) - standard = 20.50" x 42.00"
*WPC (1987 on) - standard = 20.50" x 46.00"
*WPC - superpin = 23.25" x 46.00"
*Pin2K tables = 20.50" x 43.00"

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From WMS site

"Williams' standard playfield length increased from 42" to 46" in 1988"