This book has over 1,183 entries in the dictionary section, these being mainly on playwrights and plays, but others as well including managers and critics, and also on specific theatres, legislative acts and some technical jargon.
Then there are entries on the different genres, from comedy to tragedy and everything in between.
Inevitably, the chronology is quite long as it has a long period to cover and the introduction provides the necessary overview.
The Historical Dictionary of British Theatre: Early Period concludes with a pretty massive bibliography.
That will be of use to particularly assiduous researchers, but this book itself is a good place to start any research since it covers periods that are far less well-known and documented, and ordinary theatre-goers will also find useful information.